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This Month's Featured Story
Michigan's other Petoskey Stones
Charlevoix Stones, Favosites & Fossilized Corels
We are poking fun, but Michigan is such a great place to collect rocks, why not add some more help in finding interesting stuff on our shorelines and driveways that look like Petoskey Stones, but they're not! A Pesotsky Stone is a fossilized coral, a Charlevoix Stone is a fossilized coral, and a Favosite is a fossilized coral, but a Favosite is not a Petosky stone. Clear??
The Charlevoix stone looks a lot like its cousin, the Petoskey stone. It’s smaller in total size but is especially distinguished by its smaller honeycomb-like corallite patterns. The two are sometimes confused, and it's easy to see why: Both are shades of soft gray or beige, freckled with honeycomb patterns, and are found in the same areas around Michigan, usually along shorelines in the northern parts of the state. Like the Petoskey stone, the Charlevoix stone is a remnant from the ancient period of Earth history when the land that we now call Michigan sat at the bottom of a shallow sea.
Paleontologist Jen Bauer, a research museum collection manager at the University of Michigan’s Museum of Paleontology, said that while both Charlevoix and Petoskey stones are fossilized coral, the two are from different taxonomic groups: Petoskey stones being from the major group “Rugosa,” while Charlevoix stones are from the group “Tabulata,” a nod to the tabulae, or small square-ish shapes, that make up their intricate design.
While the two groups’ time on Earth overlapped, the coral species that gave us Charlevoix stones were much longer lived. Charlevoix stone coral belongs to the now-extinct genus Favosites, which existed on the planet for nearly 200 million years, some 450-250 million years ago. Favosites consist of a series of calcitic tubes (corallites) packed together as closely as possible, thus the resemblance to a honeycomb. The openings for the coral polyps are much smaller than in Petoskey stones and look like a lace pattern draped over the rock.
Meanwhile, the genus of coral that included the Petoskey stone, Hexagonaria, was around for less time -- about 57 million years. (For a mind-bending comparison, consider that anatomically modern humans are generally believed to have been around for only about 200,000 years.)
The reason both Charlevoix and Petoskey stones are so prevalent here in Michigan is due not only to our state’s geological past but also it's present. “Michigan’s history is pretty unique,” Bauer said. “We also have these really beautiful lakes that churn up the stones. You could find these corals in other places, but you don’t find the really beautiful polished stones like you do in Michigan.”
Petoskey Stone and Charlevoix Stone
A Nice Tumble of Charlevoix Stones
The Art of Crystals from a Human Perspective
Many of us collect crystals and minerals because we find them beautiful. We would venture to guess that's what got the majority of us hooked on collecting them in the first place. We find them beautiful in many ways. But have you ever thought of using crystals as the subject of art, just like how many painters will paint a still life scene? It's not an easy thing to do. Crystals and minerals display all kinds of interesting visual characteristics like transparency, refraction, reflection, polarization, dichromism, and more. In fact, they are quite difficult to successfully depict in artistic media like watercolors, colored pencils, or even in computer-aided design programs. They are mathematical, symmetrical, and natural all at the same time.
We thought that some examples and a couple of visual tutorials might help us all pass the time and ponder the artistic beauty and difficulty of painting crystals. Check these out and see if you can do it too.
Follow the Seven Steps by CGCookie
This example works best for CGI and Oil Painting.
1) Draw the outline of your crystal or gemstone. If you're on a computer program, do this on its own layer separate from the other steps. 2) Fill it in with a solid color. 3). Add in some color tones and shades on each face. Remember to think about which way the light is pointing at your object and be consistent with how the light would hit the object. 4) Remove/Erase the outlines. 5) Add is some inclusions and refractions on the object. 6) Paint on so highlights using white or the color of your light sources that really adds contrast and depth. 7) Add in shadows and depth to make it look 3D.
Click to Download for Practice
Drawing a Cluster of Crystals
Practicing the Techniques
Click to Download for Practice
A Practice Page for Fun
Click to download this and have fun. It's no easy thing to do. It takes practice and patience to be able to color in convincing crystals and perhaps it will give you a bit more respect for those artists and scientists who spend many hours creating the illustrations that we marvel at and enjoy.
The Artist James Brunt
We have been waiting a few months for the right time to post this unique and awe-inspiring artist's work. Why did we wait you might ask? Well, because we thought his work was so unique and paid homage to the great stonemasons and neolithic builders of the past, as well as being something fun that any of us could do to emulate the wonder of what he generates. During this time that many of us are home, and perhaps are looking for ideas to do with our family or just for ourselves, we thought it would be a great time to post this.
If these inspire you, go out and create your own cairns and landscape-based art, and in turn, maybe you will inspire others too!
About the Artist
James Brunt creates elaborate ephemeral artworks using the natural materials he finds in forests, parks, and beaches near his home in Yorkshire, England. This form of land art, popularized and often associated with fellow Brit Andy Goldsworthy, involves detailed patterns, textures, and shapes formed using multiples of one kind of material. Brunt collects twigs, rocks, and leaves and arranges them in mandala-like spirals and concentric circles. He photographs his finished work to document it before nature once again takes hold of his materials. The artist frequently shares updates via Twitter and Facebook where he sometimes invites the public to join him as he works. Brunt also offers prints of his photographed artworks on his website.
Figure A: Orangish Powellite, Apophyllite, and Scolecite
Figure B: Scolecite Spray (click to enlarge)
Figure C: Scolecite Crystal needles
Figure D: Scolecite and Stilbite Spray (click to enlarge)
Figure E: Scolecite Spray (click to enlarge)
Figure F: Pale Green Apophyllite with Scolecite from India
Figure G: Scolecite carved sphere. Sometimes Scolecite is carved into sculptures and more rarely carved into gemstones.
Here we have one of the extensive zeolite family of minerals that usually precipitates from warm mineralized fluids in volcanic settings, circulating in the Earth in heated convection cells. it was first described in 1813 and named after it’s pyroelectric reaction in the flame of a blowpipe (which used to be a standard mineralogical test way back when, in this case, a voltage is generated across the crystal when heated). It is a secondary mineral, growing in cavities within the lava such as gas bubbles. It also occurs in metamorphic rocks, when fluids released from higher temperature rocks below during their transformation by heat and pressure percolate upwards and precipitate their chemical contents upon encountering different temperatures or chemical conditions.
It usually grows as sprays of needle-shaped crystals (called acicular) with lines called striations running down the faces parallel to the long axis, or fibrous aggregates. The usual color is white but pink or salmony also occurs, as do red and green. Yellow or brown fluorescence is common, caused by electrons getting excited by UV light and jumping up an energy level, then releasing the energy as visible light. It can be very brittle despite its Mohs hardness of 5.5, so specimens should be handled and stored with great care to prevent damage and extraction from the hard mother rock is delicate at best.
The Technical Stuff
Scolecite is a tectosilicate mineral belonging to the zeolite group; it is a hydrated calcium silicate, CaAl2Si3O10·3H2O. Only minor amounts of sodium and traces of potassium substitute for calcium. There is an absence of barium, strontium, iron, and magnesium. Scolecite is isostructural (having the same structure) with the sodium-calcium zeolite mesolite and the sodium zeolite natrolite, but it does not form a continuous chemical series with either of them. It was described in 1813 and named from the Greek word, σκώληξ (sko-lecks) = "worm" because of its reaction to the blowpipe flame.
The structure of the aluminosilicate framework is the same for scolecite, natrolite, and mesolite. Scolecite has long ordered chains, rotated 24° around the axis of the chain. One Calcium cation and three water molecules are in four ion sites in the channels parallel to the C crystal axis. There is no sign of aluminum ions occupying silicon ion sites.
The Many Faces of Pyrite
Pyrite is a very interesting mineral. You might know it by its other name - Fool's Gold. It's heavy, often brassy golden in color and does all kinds of interesting things. Its crystals can be iridescent, perfect cubes, diamond-shaped, pentahedrons, pancakes, massive bulky geometric conglomerates, and can even form beautiful replacement casts of fossils, making them look like gold.
Radiating Pyrite in Rock Formation - Sun or Pancake
Pyrite Pentahedron with Quartz
Iron Pyrite is an iron sulfide with the chemical formula FeS2 (iron(II) disulfide). Pyrite is considered the most common form of sulfide minerals. Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal.
The name pyrite is derived from the Greek πυρίτης (pyritēs), "of fire" or "in fire", in turn from πύρ (pyr), "fire". In ancient Roman times, this name was applied to several types of stones that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what we now call pyrite. By Georgius Agricola's time, c. 1550, the term had become a generic term for all of the sulfide minerals.
Pyrite is usually found associated with other sulfides or oxides in quartz veins, sedimentary rock, and metamorphic rock, as well as in coal beds and as a replacement mineral in fossils, but has also been identified in the sclerites of scaly-foot gastropods. Despite being nicknamed fool's gold, pyrite is sometimes found in association with small quantities of gold.
Pyrite Fossil Replacement in Ammonites
Massive Geometric Pyrite Crystal
Pyrite Cube from Spain
Iron Pyrite is a fun crystal to collect. It is usually not very expensive and, as you can see from the above pictures, it comes in many fascinating forms and is a very beautiful metallic mineral. There's always room on the shelf for one more.
What is Strontium Titanate?
Strontium Titanate is a man-made material. It grabbed public attention in the early 1950s as a diamond simulant - a material that has an appearance that is very much like diamond but has a different composition and/or crystal structure. It is one of those unique discoveries researched and developed by the National Lead Company. It had the cubic crystal structure and fire greater than that of a diamond. With this discovery, it looked like they had accomplished their goal. The result: SrTiO3 or Strontium Titanate and a material to simulate diamonds.
When cut and polished like a diamond, strontium titanate has a very similar luster, brilliance, and scintillation. However, strontium titanate has a "fire" that greatly exceeds the fire of a diamond. "Fire" is the ability of a gem to act as a prism and separate light passing through it into a rainbow of colors. The fire of strontium titanate is so strong that it immediately surprises the observer.
Between the early 1950s and the early 1970s, Fabulite, Diagem, and the other strontium titanate brands were popular sellers. Then, many people who purchased strontium titanate jewelry and wore it regularly began to notice that their stones were showing signs of wear. The facet faces were often scratched, and facet edges were often nicked and chipped. A material with a Mohs hardness of 5.5 does not stand up to wear like diamond with a hardness of 10, or ruby and sapphire with a hardness of 9.
Competition From Other Diamond Simulants
Strontium titanate does not have the hardness and toughness of diamond, and that was a problem. It only has a hardness of 5.5. That's low enough that contact with many common objects could result in a scratch or a damaged facet edge. This deficiency allowed newly developed simulants a place in the market.
Starting in the 1970s, simulants such as YAG (yttrium aluminium garnet), GGG (gadolinium gallium garnet) and cubic zirconia (CZ) quickly took market share away from strontium titanate. In the eye of many consumers, these simulants had an appearance that was similar to diamond and a durability that was superior to strontium titanate.
In the 1990s, synthetic moissanite began to replace YAG, GGG, and CZ in many of their uses. Its appearance is very similar to diamond, but it has a hardness and fire that is superior to all of these simulants from the 1970s. Cubic zirconia remains an important diamond simulant because its price is much lower than synthetic moissanite.
Today, strontium titanate is seldom seen in jewelry; however, it still has a more impressive fire than any natural or lab-created gemstones that are frequently seen in jewelry. It remains an attractive and satisfactory stone for earrings, pendants, and brooches that will encounter little abrasion or impact.
Tausonite - The Strontium Titanate Mineral
Naturally occurring strontium titanate was not known as a mineral until its discovery in 1982. It was first found in Eastern Siberia, Russia, and later occurrences were found in Paraguay and Japan. It is a very rare mineral, found in tiny cubic crystals, crystal clusters, and irregular masses. Natural specimens are typically so small and so rare that they have no commercial use beyond mineral specimens.
Comparison of Diamond Simulants
Strontium Titanate dispersion: The photos above show how strontium titanate has a spectacular dispersion when compared to moissanite, CZ, and diamond. Its dispersion is a little less than double that of moissanite, triple that of CZ, and more than quadruple that of diamond. In the photo above, the strontium titanate is a 6-millimeter round. The other stones are 4-millimeter rounds. This difference in size does give strontium titanate an advantage.
On a quick visual inspection, an experienced person will see that the dispersion of strontium titanate instantly stands apart from diamond, diamond simulants and moissanite. Strontium titanate sometimes contains bubbles that reveal its lab-created origin, and this distinguishes it from diamond. The much lower hardness of strontium titanate is usually obvious in jewelry that has been worn frequently as they exhibit levels of abrasion that are rarely seen in diamond, YAG, CZ, and moissanite.
The Michigan State Gem
Isle Royale Greenstone
The official State Gemstone of Michigan is the Isle Royale Greenstone (Chlorastrolite). This was picked in 1972 to be the Michigan Gemstone after the lapidary community lobbied the State Legislature to pass it into law. Reportedly the lawmakers had some smart remarks to make before they were finished. Governor Milliken signed the Bill. One Senator from Kalamazoo (Anthony Stamm), said It looks like stuff I put on my driveway at $40 a load. Another legislator wanted to know if Chlorastrolite was any relation to the stuff that clogs arteries. Another lawmaker explained If you think my wife is going to trade in her Diamond for a Greenstone, you have rocks in your head.
Chlorastrolite is Hydrous Calcium Aluminum Silicate. It commonly has a polygonal mosaic pattern sometimes referred to as an alligator pattern. Chlorastrolite is a variety of the mineral Pumpellyite. It can be light or dark green, but the pattern is much showier in lighter shades. Lighter green predominates Greenstones from Isle Royale, while many Keweenaw Greenstones are darker. A desirable Greenstone trait shows radiating lines exhibiting Chatoyancy like Tiger-eye. A solid Greenstone has a hardness of 5.5 to 6.
Chlorastrolite is formed in vesicles (small holes in bubbly Botryoidal lava) in the upper strata of the lava flows. In many cases in the Keweenaw, the vesicles do not completely fill, and you get hollow nodules. If you're really, really lucky, these might fill in with Copper, Prehnite, or Thomsonite, making them an extraordinary find.
The mineral's history dates back roughly 1.1 billion years ago, to the age of the Midcontinent Rift: A time when North America began to split apart at the seams, causing lava to spill out of the Earth's crust along a fissure that ran from Kansas up to present-day Lake Superior and back down to where Detroit now is. Those lava flows, which could be thousands of feet thick in some places, eventually cooled into a rock we call basalt. Within that basalt were small pockets of empty space left behind from gasses in the lava – and that is where chlorastrolite eventually formed.
Of all the land along that original Midcontinent Rift, the Lake Superior region is the only place where those veritable floodplains of basalt became exposed, making it the only place to find chlorastrolite. Adding to its scarcity, chlorastrolite is also difficult to find because of its size. Large pieces are very rare; more often they are found as pea-sized nodules or needle-shaped crystals lodged within larger chunks of basalt or, when water has eroded the basalt around it, as pebbles or even granules.
A Greenstone found underwater off Isle Royale in1961 by Arthur Vierthaler is in the Smithsonian and is claimed to be the largest Greenstone ever found at one and a half inches by three inches.
Its usually found as bean-sized, rounded beach pebbles in Michigan. Collecting Chlorastrolite from Isle Royale National Park is now prohibited). Polished stones are used for stickpins, rings, earrings, cuff links, pendants, and sometimes incorporated into inlays and mosaics. Because Michigan Greenstones come from such a limited area of the world, few people have ever seen one. They are basically a one source gemstone and that source is the Isle Royale National Park, (where they’re illegal to remove), or in the Keweenaw Peninsula, where they’re becoming more scarce because of all the Private property and all the old dump piles having been crushed and hauled away for road fill.
Chlorastrolite is a bluish-green to dark green stone with a pattern of slender, star-like crystals which results in a "turtleback" pattern. Some chlorastrolite includes other minerals, which produce additional colors. Other names for the Greenstone are "green star stone" or "turtleback". It does look very much like a turtle shell!
The Giant Sea Scorpion
Giant Sea Scorpion Tracks Discovered in Scotland
330 million-year-old tracks made by a giant Arthropod, which was longer than a man, have been discovered in Fife (south-eastern Scotland). The trackway consists of three parallel lines representing the feet and in between a “scooped” out shape indicating that the tail was dragged; have been preserved in sandstone and were discovered by chance when Dr. Martin Whyte from the University of Sheffield was out walking.
The tracks have been ascribed to a sea scorpion called Hibbertopterus, fossils of which have been found in the area. Sea scorpions, or to be more precise Eurypterids (pronounced: You-ree-ip-ter-ids) were Chelicerate Arthropods that evolved around 480 million years ago and flourished worldwide in marine and freshwater environments until their demise towards the end of the Permian.
Fossils of Eurypterids are relatively common in ancient marine strata, as like Trilobites, they had to shed their body armor (exoskeleton) when they grew and the cast shells had a high preservation potential. Most Eurypterid fossils are not the fossilized carcass of a dead animal but instead are the fossilized remains of a cast-off shell from a molt.
Some types of Eurypterids grew to enormous sizes and until the rise of vertebrates such as fish, they were some of the top predators of the Palaeozoic. Click to read an article about the discovery of an enormous 3-meter long sea scorpion: Claws! Giant Sea Scorpion of the Devonian
This Scottish discovery is the largest known walking trackway of an Arthropod, or indeed any invertebrate discovered to date.
Size Comparison and Artist Rendering of the Giant Sea Scorpion
Image Credit: Bristol University
Image Credit: Wikipedia Commons
The tracks were probably made as this huge animal hauled itself out of the water. Eurypterids, with their simple gills, were adapted to absorb oxygen from both water and the atmosphere. It is likely these animals moved into the shallow waters in order to breed, just like a relative of these creatures, the Horseshoe Crab does today.
The tracks are already quite badly eroded but removing the sandstone rock in which they are preserved may be too difficult. Instead, Scottish Natural Heritage is funding a project to create silicone copies of the trackway which will enable these ancient “footprints” to be studied in detail. A spokesperson for Scottish Natural Heritage, described this discovery as “unique and internationally important because the creature was gigantic.”
Richard Batchelor from Geoheritage Fife, commented:
“The trackway is in a precarious situation, having been exposed for years to weathering. The rock in which it occurs is in danger of falling off altogether. Removing it and housing it in a museum would be prohibitively costly but molding it in silicone rubber and making copies for educational and research purposes means that we can still see and research this huge creature’s tracks in years to come.”
The sandstone has been dated to approximately 330 million years ago (mid-Carboniferous). This area of eastern Scotland is world-famous for its Carboniferous fossil sites. For example, at East Kirton, a number of important fossil-rich Mississippian (Lower Carboniferous) strata are known. It seems that around 330 million years ago, this area of Scotland was low lying with many freshwater lakes. Many early Tetrapod fossils, as well as numerous invertebrate fossils and plants, are known from this region.
Gemmy Fossils Reveal New Dinosaur
Image Credit: James Kuether
Four members of this newly described plant-eater were found together in what may be Australia’s first known dinosaur herd.
Unusually colorful fossils found in Australia belong to a stunning new species of plant-eating dinosaur, scientists report today in the Journal of Vertebrate Paleontology. The remains not only belong to the first herd of dinosaurs discovered in the country, but they also represent the most complete dinosaur fossil yet found preserved in opal.
Discovered near the town of Lightning Ridge, about 450 miles northwest of Sydney, the hundred-odd bones have a rare blue-grey hue with occasional flashes of brilliant gem-quality color. Lightning Ridge is famous for yielding fossils hewn from often brightly colored opal, a gemstone that forms over long periods from the concentration of silica-rich solutions underground. But finding a whole new dinosaur species is remarkable.
“Any time we find a new Australian dinosaur it’s interesting because we have so few,” says Stephen Poropat, a paleontologist from Swinburne University of Technology in Melbourne who was not on the study team. The tally of known Australian dinosaurs is currently around 24, he notes, including Weewarrasaurus, another species from Lightning Ridge described last year.
The newest species, Fostoria dhimbangunmal, was an Iguanodon-like dinosaur that lived about a hundred million years ago during the mid-Cretaceous period when this region was a broad floodplain with lakes and rivers flowing into the inland Eromanga Sea. “The floodplains were frequently wet and richly vegetated, meaning they were a good place for plant-eating dinosaurs,” says study leader Phil Bell, a paleontologist at the University of New England in Armidale, New South Wales.
Studying dinosaurs from the time slice at Lightning Ridge is important, Poropat adds, as the world was then experiencing the warmest conditions of the past 150 million years. “These dinosaurs were living in a really incredible greenhouse Earth,” he says. “The globe would have potentially looked quite different, and these fossils can tell us how these dinosaurs were coping.”
Right: This fossil is part of a vertebra from the back of a Fostoria dinosaur.
Left: This fossil toe bone belonged to a member of Fostoria dhimbangunmal. The fossils were all found in a former opal mine and show glimmers of the brilliantly colored gemstone.
Bundle of Bones
Long-time Lightning Ridge opal miner Bob Foster found the fossil in 1986. Scientists at Sydney’s Australian Museum, along with Australian Army reservists, helped Foster excavate the find as an accumulation of dinosaur bones embedded in blocks of rock, with the museum then taking the fossils into their collections.
But the fact they were left languishing unstudied for 15 years or so and put on display at a Sydney opal store led Foster to decide to reclaim his discovery. He returned it to Lightning Ridge, and his family eventually donated it to a local museum, the Australian Opal Centre, where Bell was able to study the find.
“We originally thought it was one skeleton, but once we began to study the individual bones, we realized … there were parts of four scapulae, or shoulder blades, all of different sizes,” he explains. About 60 of the bones are from a probable adult that was 16 feet in length, while the others are from juveniles of various sizes, prompting Bell to speculate that they were the remains of either a family or small herd of herbivorous dinosaurs.
“We have bones from all parts of the body, but not a complete skeleton,” he says. “These include bones from the ribs, arms, skull, back, tail, hips, and legs. So, it’s one of the most completely known dinosaurs in Australia … [with] 15 to 20 percent of the skeleton of the species.”
The name Fostoria honors Bob Foster, while the species name dhimbangunmal means ‘sheep yard’ in the local Yuwaalaraay and Yuwaalayaay Aboriginal languages. It was chosen by Foster’s wife Jenny, who is Gamilaraay Aboriginal, to honor the Sheepyard locality where Foster’s, now defunct mine once operated.
Image Credit by [cisiopurple]
About the length of an elephant, Fostoria would have habitually walked on its hind limbs, though the scientists surmise it sometimes used all four to get around. It likely ate primitive plants called horsetails as well as bunya and hoop pines, fossils of which are also found in the region. (Find out about a sauropod dinosaur that likely crawled as a baby and walked on two legs as an adult.)
A relative of Iguanodon and Australia’s most famous dinosaur, Muttaburrasaurus, Fostoria is also an early member of a group that would elsewhere evolve into the duckbilled hadrosaurs, which were common in North America and Asia toward the end of the time of the dinosaurs, roughly 66 million years ago.
“Early duckbill dinosaurs were the primordial soup from which the fantastical crested species … later evolved,” says Lindsay Zanno, a paleontologist at the North Carolina Museum of Natural Science in Raleigh who was not involved in the research.
“Although the pace of discovery of early duckbills like Fostoria has intensified around the globe, we still have much to learn about how these herbivores became so successful,” she adds.
Image Credit: Evgenia Arbugaeva/National Geographic Magazine
The New Ivory Trade
We held off a bit before publishing this article because we had a speaker come in to discuss the extinction of Woolly Mammoths and Mastodons. We wanted to see what additional information he would shed on this subject before we wrote on the subject.
While it is true that the buying and selling of Ivory tusks from Elephants has been outlawed and is illegal in most countries with international trade being largely shut down, black market ivory selling still goes on and much of it goes to China. However, there is a new source that is being poorly tracked and is a tricky subject. This is the new market for selling Mastodon and Mammoth Ivory on the Black Market. Some see this as much more ethical that poaching live elephants, and we would agree with that sentiment, but its also robbing the scientific community the chance to learn why these animals became extinct.
Basically, in isolated regions of Russia's Siberia, Ivory hunters are traveling by sea, land, and air to get to the frigid areas that have been melting away rapidly over the last two decades. Many of these hunters are very poor, have little opportunity for work, and have hungry mouths to feed at home.
The most likely cause for the recent melting of the permafrost is global climate change brought about by man's activities. In reality, as the permafrost thaws, it releases more and more greenhouse gasses into the atmosphere creating more melting and hotter temperatures around the world.
Siberian Tusk Hunters use water hoses and horses to cut away at the frozen ground to dig deep holes into the soils causing it to melt much faster to excavate caves and hunt for tusks and Woolly Rhinoceros horn. Rhinoceros horn is valued like gold in Eastern Countries because folk medicine believes that it has powerful medicinal qualities. A five-pound Rhino horn can sell for over $11,000 to wholesalers in Vietnam.
The hunters risk their lives in mosquitos infested forests, frigid temperatures, remote locations and crawl back into caves, that are starting to collapse as soon as they dig them out, for a chance at a small fortune in the new ivory trade.
The Mammoth tusk this man is carrying will be worth about $34,000. Image Credit: Amos Chapple
Photo Credit: Associated Press. A Complete Mammoth skeleton sold for over $645,000 in 2017.
Woolly Mammoth Pistol Grip from Ivory found in Alaska.
Mammoth molar sold as is. These teeth are sometimes slabbed to make knife handles, jewelry and other objects of art.
Ivory artifacts from the Yanaste Complex in Siberia. Shown here are spear points, needles, a scoop, bracelet and diadem. Our ancestors had an affinity for ivory as well.
Carmeltazite - Harder than Diamonds?
Extraterrestrial Mineral Harder than Diamonds Discovered in Israel
Original Article by Helen Flatley in the Vintage News
A new discovery in the mountains of northern Israel has caused significant excitement for geologists around the world. While working in the Zevulun Valley, close to Mount Carmel, Israeli mining company Shefa Yamim found a new mineral never before discovered on earth.
The International Mineralogical Association regularly approves new minerals for its official list, with up to 100 new substances added to the register each year. However, this latest discovery was hailed as a significant event, as it was previously believed that this type of mineral was only found on extraterrestrial material. The new mineral substance has been found to naturally occur on Earth.
The CEO of Shefa Yamim, Abraham Taub, told Haaretz that the mineral had been named carmeltazite, after the place of its discovery. The elements contained within its structure: titanium, aluminum, and zirconium were previously found in allendeite, a mineral seen on the Allende meteorite that fell to earth in February of 1969.
While the majority of the new minerals approved by the International Mineralogical Association are unspectacular in appearance, carmeltazite offers considerable commercial opportunities, as it resembles other gemstones used in the making of jewelry.
This strange new mineral was found embedded in cracks within sapphire, the second hardest mineral (after diamonds) found to occur naturally on earth. Carmeltazite closely resembles corundum (sapphire or ruby) in its chemical composition and is found in black, blue-green, or orange-brown colors, with a metallic hue. However, after density testing, scientists discovered that carmeltazite is even denser than diamond, and is significantly scarcer, making its value extremely high.
According to the BBC, the region close to the Savulun Valley in Isreal is known for volcanic activity dating from the Cretaceous period. The Carmel range is home to at least 14 volcanic vents that created the geological conditions for the formation of carmeltazite, over extremely long periods. It is thought that carmeltazite formed 18 miles under the surface of the earth, close to the crust-mantle boundary. High pressure and temperatures produce partially molten rocks that release fluids and react to form new minerals. As vents emerge in the surface of the earth, this volcanic matter is rapidly transported into the upper crust along with other materials, creating the type of deposits found in Mount Carmel.
The mining company has been working intensively in this region due to the possibilities offered by this rich geological legacy. Although they were principally looking for sapphire, the new mineral was discovered embedded in the gemstones they harvested and had analyzed. The mining company has recovered many samples but carmeltazite remains extremely rare. The largest stone discovered to date reached 33.3 carats. Haaretz reports that the mineral has been trademarked by the mining company as “Carmel Sapphire” and it has recently been approved as a new mineral by the International Mineralogical Association’s Commission on New Minerals.
Although the Commission regularly approves new discoveries, it is unusual to find a substance so spectacular in appearance and quality, and a result has attracted a significant amount of international attention. To date, carmeltazite has only been discovered in the Zevulun Valley, which means it is one of the rarest minerals in the world and is also likely to be one of the most expensive.
CEO Taub stated that the company intends to market the mineral as a gemstone, and potentially use it in the production of high-end jewelry. One thing is sure: this mineral is likely to command a monumental price tag when it eventually hits the market.
But is it harder than Diamonds?
The original reports that MMS could locate do not specify the hardness of the new mineral. It is, in fact, a variant of corundum (an Aluminum Oxide) with elements of Titanium and Zirconium. Both Titanium and Zirconium Oxides are hard, and the mineral Carmeltazite is denser than diamonds, but it's unlikely to be harder than diamonds. On Mindat.org the chemical formula is listed as ZrAl2Ti4O11. This combination of chemical bonds will more likely place Carmeltazite closer to 8.7 to 9.4 on the mols scale with the Titanium-Zirconium elements. However, there is a big difference between 9 and 10 in the mols hardness scale. Zirconium-Titanium alloys are known of in metallic forms, but being that carmeltazite is formed in heavy pressures and heat, perhaps it will have other properties in wear resistance or tensile strength that will lead to new discoveries?
Proposed Chemical Structure of Carmltazite
Rainbow Flame Obsidian
Beautiful to behold and even more amazing when polished into cabochons and items, Rainbow Flame Obsidian is subtle and complex in its color sheen. There are few words to describe its unique characteristics other than it's got a really cool name to go along with its labradorescent like color play.
Rainbow Obsidian is obsidian volcanic glass that has multicolored iridescence caused by inclusions of magnetite nanoparticles. The magnetite particles interfere with light that passes into the semi-transparent mineral structure and creates the rainbow sheen. While Obsidian is often thought of as nature's glass or black volcanic glass, there are a number of varieties that collectors are interested in finding.
Some varieties include Mahogany Obsidian, Snowflake Obsidian, Golden Sheen Obsidian and the topic this month of Rainbow Obsidian. Consequently, Rainbow Obsidian comes in several varieties based on their color quality, similar to Opals. Some Rainbow Obsidian names are Velvet Peacock, Flame, Banded, and Iris Obsidian, to name a few. It has been cut and polished into jewelry pieces for centuries and is famously sharp when knapped. Modern-day flint knappers have discovered this amazing varietal and are producing some stunning artifacts as we will show you below.
Rainbow Obsidian is coming mostly from Mexico and Oregon that is available in the United States. Rainbow Obsidian comes from three very specific places. In Lake County, Oregon from the Glass Buttes, the Modoc Plateau near Davis Creek, California, and La Revoltosa Mine in Jalisco Mexico. Generally speaking, Obsidian is not an expensive collector's item but the vibrant colors in Flame Obsidian will fetch a premium price. It also becomes more expensive outside of North America and is best used for trading with other collectors from other countries who don't see it as much as we do here.
Obsidian is a natural glass and may have razor-sharp edges that can easily cut skin and flesh. Handle with care. Do not grind this mineral dry since long-term exposure to finely ground powder may lead to silicosis.
Rough Rainbow Iris Obsidian Rock
Velvet Flame Obsidian Arrowhead
Knapped Rainbow Obsidian Spearhead
Oregon Fire Obsidian
Velvet Peacock Obsidian
Archaeologists in Spain Discover a Cache of
Prehistoric Crystal Artifacts
Archaeologists in Spain have unearthed an extremely rare set of weapons, including a long dagger blade, twenty-ﬁve arrowheads, and cores used for creating the artifacts, all made of crystal! The finding was made inside megalithic tombs dating to the 3rd millennium BC in the southwest of Spain.
An excavation of megalithic tombs in Valencina de la Concepción in Spain led to the dramatic discovery of the rare relics, which experts described as exceptional and magnificently well-preserved. The objects are estimated to be over five thousand years old (dating back to at least 3000 BC). As the Daily Grail writes, the Montelirio tholos, excavated between 2007 and 2010, is a great megalithic construction which extends nearly 44 meters (144 ft) in total, constructed out of large slabs of slate. At least 25 individuals were found within the structure. Analyses suggested that there was one male and numerous females who had drunk a poison substance. The remains of the women sit in a circle in a chamber adjacent to the bones believed to be of their chief.
There are no crystal mines in the nearby proximity which suggests that the creators of these objects must have traveled many hundreds of kilometers to source their material. The scarcity of crystal rock in addition to the enormous amount of craftsman the construction of the artifacts involved suggests that these were elite products. Given that the crystal weapons were in a tomb, it suggests that they were used as highly sought after funerary items given to select individuals for ceremonial purposes.
Both Images: The crystal dagger blade. © Morgado, A., et al.
The blade is 214 mm in length, a maximum of 59 mm in width and 13 mm thick.
In addition to the human remains and textiles, ivory tusks and carvings, the archaeologists found the large hoard of crystal arrowheads. The fact that they were discovered altogether indicates that they could have been a ritual offering at an altar. The arrowheads have the distinctive long lateral appendices of flint arrowheads from the region, but archaeologists noted that even greater skill must have been required to produce these unique features when using rock crystal.
The predictable conchoidal (semi-circular) fracture patterns you get from flint, chert, and obsidian make them fantastic materials to work. Crystals of this sort have a vastly different microscopic crystalline structure and would behave completely differently when struck. I can’t imagine where you would even start to develop the proper technique except for many years of trial and error.
A: Ontiveros arrowheads;
B: Montelirio tholos arrowheads;
C: Montelirio dagger blade;
D: Montelirio tholos core;
E: Montelirio knapping debris;
F: Montelirio micro-blades;
G: Montelirio tholos micro-blades;
Photograph: Miguel Angel Blanco de la Rubia.
The Sad and the Amazing
The area that was excavated held secrets to an undiscovered civilization that lived in the area that had built a large settlement at least 5000 years ago. These tools and other artifacts are currently being studied and are considered priceless because they point to an unknown culture that existed in Western Spain leading to additional speculation into an advanced, unknown people who inhabited, not only the Iberian peninsula, but branched out into African and the Atlantic Ocean long before historians have documented its existence. Sadly, the small teams of Archaeologists had to file injunctions to stop construction over the site of shopping malls, apartments, and parking lots. As a result, they could only study the site for three years.
Interestingly though, despite being found relatively frequently in burials of the 4th and 3rd millennia BCE, crystal implements disappear from later funerary monuments in the Early Bronze Age (beginning of the 2nd millennium BCE) - a "truly striking" development, researchers say, as it would seem "the use of this raw material as grave goods was almost entirely abandoned", although the reasons remain a mystery.
How to tell the Difference between Jasper, Agate, Chalcedony, and Geodes
If you read about the gem materials used for lapidary work and rock tumbling, you will encounter three names over and over again. These are "Agate", "Jasper", and "Chalcedony." These names are often misunderstood and often used incorrectly. With a little knowledge, you can use these names correctly for most specimens. However, some specimens can be difficult or impossible to name correctly with these terms if you must rely only on visual inspection of the material.
We would like to provide a short lesson on these names to help you understand them and use them correctly - as much as that is possible. The simple answer is if you put a light behind the material and you can see through it, then it is an Agate and if you can’t, then your holding Jasper. The more complex answer is that it is not always that straightforward. The simple science behind this question is that both Agates and Jaspers are comprised of Quartz - which is one of the most common minerals on the planet. Quartz is comprised of two major types: macrocrystalline (large crystal) and cryptocrystalline or microcrystalline (small crystal).
What is Chalcedony?
Chalcedony is a generic name given to materials that are composed of microcrystalline quartz. Agate and jasper are both varieties of chalcedony.
What is microcrystalline quartz? "Quartz" is a mineral composed of silicon and oxygen (SiO2) and the word microcrystalline means that the quartz is in the form of crystals that are so small that a microscope must be used to visualize them individually. Sometimes the word "cryptocrystalline" is used instead of "microcrystalline" but both of these words are imprecise ways of communicating a microscopic size.
Chalcedony is a very hard material. It has a hardness of 7 on the Mohs scale. It breaks with a conchoidal fracture, and freshly broken pieces have a very smooth, non-granular texture and a waxy to vitreous luster. These characteristics enable chalcedony to be cut and polished into bright, durable gemstones. Varieties of chalcedony are favorite materials for making tumbled stones.
Chalcedony occurs in a wide range of colors. It is commonly gray, white, brown, red, yellow, orange and black, but it can occur in any color. It can also be banded or have plume, dendritic, mottled, mossy or other colorful structures contained within its structure. At one time the word "chalcedony" was reserved in parts of the gemstone industry for a light blue translucent material; however, this use of the word has nearly disappeared.
Chalcedony includes Carnelian, Chrysoprase, Agate, Bloodstone, Jasper, and others. When Chalcedony is in concentrically banded patterns it is called an Agate. Occasionally the banding is larger than the crystal and the banding is not visible- like with most Carnelian.
Light Blue Chalcedony Tumbled Stones
What is Agate?
Agate is translucent to a semi-transparent form of chalcedony. If you have a piece that is semi-transparent you will be able to hold a very thin piece up and see distorted or foggy images through it. If you hold a translucent piece up to a source of light you will see a small amount of light passing through the thin edges.
Agate is generally a banded material, and observing bands in a specimen of chalcedony is a very good clue that you have an agate. However, some agates do not have obvious bands. These are often translucent agates with plume-shaped, dendritic or mossy inclusions.
Many agates form in areas of volcanic activity where waters, rich in dissolved silica (SiO2), flow through fractures and cavities in igneous rocks. When the solution is highly concentrated with dissolved silica, a silica gel can form on the walls of these cavities. That gel will slowly crystallize to form microcrystalline quartz.
Over time, additional layers of gel are deposited and these form younger bands of microcrystalline quartz on the walls of the cavity. If the dissolved mineral composition of the silica-rich water changes over time, impurities (elements other than silicon and oxygen) can be incorporated into the gel and into the microcrystalline quartz. These impurities can alter the color of the microcrystalline quartz. This can produce the color banding. Crystallization of foreign materials is often what forms the plumes, dendrites, or mossy structures that are often seen in translucent agate.
Although agates typically form in igneous rocks such as basalt, rhyolite, and andesite, they can also form in sedimentary rocks such as limestone. All of these types of rock are more susceptible to weathering than agate. So when the rocks are eventually broken down by weathering, the durable agates will remain. This is why agate nodules are often found in stream valleys that cut through fine-grained igneous rocks or limestone.
Lake Superior Agates
What is Jasper?
Jasper is an opaque variety of chalcedony. Opaque means that light does not pass through.
Microcrystalline quartz in its pure form is semi-transparent. When a small amount of impurities or foreign materials are added, the color of the microcrystalline quartz changes and its ability to transmit light decreases. Jasper contains enough impurities and foreign material to render it opaque. So, the real difference between Jasper and agate is the number of impurities and foreign material contained with a specimen.
Jasper is an opaque rock of virtually any color stemming from the mineral content of the original sediments or ash. Patterns arise during the consolidation process forming flow and depositional patterns in the original silica-rich sediment or volcanic ash. Hydrothermal circulation is generally thought to be required in the formation of Jasper.
Jasper can be banded or striated, depending on how it formed, and are most commonly red, yellow, green, brown or a mixture of these colors. The banding in agate is based on periodic changes in the translucency of the agate substance. Layers appear darker when they are more translucent (this may appear reversed in transmitted light). This effect may be accompanied and amplified by changes in the color of neighboring layers, due to other co-precipitated minerals.
While agate is typically a material that forms in the cavities of igneous rock or limestone, Jasper often forms when fine particulate materials are cemented by silica. This often occurs in soft sediments when silica precipitates and cements them into a solid mass. These included particles are what give Jasper its color and opacity. A sedimentary material is known as chert forms in extensive bedded deposits. It is also an opaque variety of chalcedony that can be called a "Jasper."
Jaspers are also known to form when volcanic ash or fine pyroclastics are cemented into a solid material from the precipitation of silica from solution. The cementation process is sometimes so aggressive that the sediment, ash or volcanic particles are dissolved or recrystallized into microcrystalline quartz.
Jaspers of Several Colors
What is a Geode
Geodes are rocks that are hollow inside, rather than solid all the way through. Geodes are generally round, though some are egg-shaped. They can range from the size of a nut to several feet. Most geodes are approximately the size of a basketball. When broken or cut open, geodes reveal a lining of crystals or other materials inside. Many of these crystals can be quite beautiful, such as the purple quartz known as amethyst. Some geodes even contain liquid petroleum. Calcite geodes contain white crystals, but sometimes these can be other colors, and under fluorescent light, additional colors show up. Other examples of geode interiors include celestite, agate, smoky quartz, and rose quartz. Chalcedony is a common mineral coating for many geodes, and it is permeable to water over time. Anhydrite geodes have interiors that resemble cauliflower. Other examples of minerals found in geodes include gypsum, calcite, dolomite, pyrite, ankerite, celestite, aragonite and goethite.
The System of Assigning a Name
Chalcedony is a name that is based upon two things: 1) crystal size, and 2) composition. Chalcedony is microcrystalline quartz. Easy!
Agate is a name based upon three things: 1) crystal size, 2) composition and 3) how light passes through the mineral. Agate is microcrystalline quartz with a translucent to semitransparent diaphaneity. Easy!
Jasper is a name based upon three things: 1) crystal size, 2) composition and 3) diaphaneity. Jasper is microcrystalline quartz with an opaque diaphaneity. It is opaque because it contains enough non-chalcedony material to interfere with the passage of light. Easy. Jaspers can be confusing to identify as well from the multiple colors and names that they are sold under and some names are not consistent from place to place.
Geode is a rock that is hollow on the inside. The only way to find out for sure if a rock is a geode is to break it apart by tapping it with a hammer, or have someone cut open the rock with a powerful saw. You'll know once you see the interior and whether or not there is a hollow or solid composition. The hollow ones are geodes, and as mentioned before, are often lined with crystals or layers of minerals. Some geodes are highly sought after and can be polished after being cut.
If you have a piece of chalcedony, determining if it is an agate or a jasper is easy when that material is clearly semitransparent, translucent or opaque. However, it can be difficult to determine the boundary between translucent and opaque. In addition, some specimens can have translucent zones and opaque zones. What are they called? Some people have solved this problem by using the term "jaspagate" or "jasper-agate" when a specimen contains zones ofboth jasper and agate. Anyone who is correctly using the name "jaspagate" has probably given a rock more than a casual look.
Mucking things up a bit...
Dalmatian Stone: The material is known as "dalmatian stone" because it is a white rock with lots of black spots, has often been called "dalmatian jasper." However, we sent some out for analysis and learned that it was not Jasper at all, but an igneous rock composed of tiny grains of white feldspar and black grains of a hornblende group mineral. Dalmatian stone is often dyed, so if you see a stone with black spots and an outrageous color (like the blue, red, green and purple stones at right) it might be dalmatian stone.
Picasso Stone: This material is known as "Picasso stone" because it looks like an abstract painting. Many people also call it "Picasso Jasper". However, this material is not a "Jasper". It is actually dolomite (a dolomitic marble to be more precise) that is mined in Utah. Dolomite is a carbonate rock that is very different from quartz. It is very soft for a gem material with a hardness of only 4 on the Mohs scale.
Ocean Jasper: The material known as "ocean jasper" is reported to be silicified rhyolite - another igneous rock. Ocean Jasper is a really interesting material mined in the country of Madagascar (an island nation off the southeastern coast of Africa. If you look at it closely, many pieces will contain concentric orbs, translucent banded agate, opaque jasper, and vugs lined with druzy quartz crystals. It is a "Jasper" and much more!
Petrified Wood: We don't want to start any arguments, but much of the material called "petrified wood" is composed of chalcedony with an opaque diaphaneity. Shouldn't that make it "jasperized wood" or at least a variety of Jasper? Something to ponder. Many people don't realize that petrified wood is found at many locations from around the world. Petrified wood for rock tumbling can be a mix of samples from Arizona to China or a mix of petrified wood from many locations in the United States.
Green Tree Agate and Green Moss Agate: These materials are often genetically related - that means they form under similar conditions. Green moss agate is a semitransparent agate with green mossy inclusions inside. Green tree agate is a white jasper with green mossy inclusions inside - however, they are only visible where they are exposed at the surface. Green moss agate and green tree agate have been found together in the same deposit - having formed just a short distance from one another.
Bumblebee: This exceptionally colored material is often called "bumblebee jasper" or "eclipse jasper". It forms on the island of Bali near the hot vents of an active volcano named Mount Papandayan. As a banded material, and for that reason, some people want to call it "agate." It is an opaque material, and for that reason, some people want to call it Jasper. However, it is neither. It is a lithified sediment that contains a volcanic brew of materials that include: volcanic ash, gypsum, barite, sulfur, and even some orpiment (an arsenic mineral!). It is often cut into cabochons, but much of what is cut is stabilized with resin because it is soft, porous and fragile. Not recommended for rock tumbling!
Veszelyite is a rare, but beautiful copper and zinc phosphate mineral. Specimens often command some fairly lofty prices for even diminutive specimens, which is a direct testament to veszelyite's rarity and attractiveness. It has a nice emerald-green to green-blue color and a high luster which produces a good colorful sparkle. Crystals are often randomly and individually attached on specimens much like green sprinkles that are spread on an ice cream cone. larger Crystal of Veszelyite can look very much like Azurite or other copper-bearing minerals. It has the distinctive blue-green color so many other copper ores. It also can resemble Dioptase and Viviandite in form and color.
Veszelyite falls in the phosphate group of minerals with a chemistry of (Cu, Zn)3PO4(OH)3 - 2H2O, Hydrated Copper Zinc Phosphate Hydroxide. It is really only valued for its rarity as a mineral specimen and its usually associated with quartz, zinc secondary compounds and copper ores like malachite and hemimorphite.
It was named after the Hungarian engineer A. Veszelyi (1820-1888) who discovered the species. It is a fairly soft mineral with a Mohs hardness of about 3.5 to 4, so it is not suitable for jewelry. It is found in Kipushi, Shaba, Rep. of Congo; Kabwe, Zambia; Moravicza, Banat, Romania, and the Black Pine Mine, Montana, USA.
Image Credit: Brad Zylman
The Little Fossil that CoulD
This Mesosaurus fossil was obtained legally from Brazil back in the 1960s and remained in a personal collection for several decades until it was donated to MMS in 2017. Because the fossil was broken across its vertical center, MMS had the fossil stabilized (you can see the crack in the picture). There are only a few of these fossils in circulation and to find one is a very good day.
Our little Mesosaurus lived during the early Permian Period in what is now Africa and South America. If you look at Mesosaurus pictures, you may jump to the conclusion that this animal was some sort of prehistoric crocodile. After all, it does kind of look like one. However, that would be the wrong conclusion to make. That’s because, while this reptile looked very much like a crocodile and lived a semi-aquatic lifestyle, its teeth give its true identity away. This animal’s teeth were very thin and were used to filter plankton and not to bite into fish or small animals. Not to mention the fact that it was quite a bit smaller than most of the prehistoric crocodiles that would come later.
An adult Mesosaurus was approximately 3 feet long and weighed around 20 pounds. That made it the size of a yardstick and about the weight of a Dachshund dog. It was an anapsid reptile – which means it didn’t have the openings in the sides of its skull that therapsids and pelycosaurs had. It was in the same classification category as turtles are today. It would roam the shoreline of rivers and lakes looking for small marine organisms and would occasionally get in the water to eat its favorite food: plankton. It would catch the plankton by filtering fresh water through those oddly shaped teeth.
One of the most fascinating facts about Mesosaurus, however, is the fact that it was instrumental in proving continental drift theory. It lived in both eastern South America and southern Africa. However, since it only swam in fresh water, it is highly unlikely it could have crossed the Atlantic Ocean to get from South America to Africa. This most likely means that these two areas were connected at one point in time and over time, spread apart. The theory that is known as continental drift changed how we see geology and our world today.
Story Credits: Wikipedia.com, newdinosaurs.com, Brad Zylman
A Rare and Wondrous Gemstone
Originally discovered in 1967, the dark and stormy stone known as Musgravite comes in on our list of rare gemstones you’ve probably never heard of. It certainly isn’t as well-known as rubies and sapphires, but you can expect to pay a steep price for this gorgeous example of Mother Nature’s talents.
The high pricing can be attributed to the stone’s rarity. Musgravite was first found in the late sixties and was named for the area of Australia in which it was discovered – the Musgrave Ranges.
The gorgeous color of this gemstone is formed when there are the perfect percentages of magnesium, iron, and zinc present. Because it requires such precise conditions, the stone is far from common. That rarity, combined with an undeniable beauty makes this a very pricey gem. You can expect to pay approximately $6,000 or per carat. In some instances, the price has been pushed to as much as $35,000 per carat. For many, it is considered a worthwhile investment, because the stone is so gorgeous – ranging from a deep gray to a soft purple. Some variations could be mistaken for amethyst, a much more common and less-expensive gemstone. However, do not be fooled. Musgravite is its own entity and worthy of the praise it has received through the years. Furthermore, it is much harder than amethyst, which is a member of the quartz family. While quartz is generally graded at a 6.5 to 7, Musgravite is ranked at an 8 or 8.5, which places it closer to topaz on the scale. That also means that this is a very durable stone that would be well placed in a ring or bracelet setting, able to hold up to regular wear and tear.
Musgravite is a rare mineral closely related by composition to the mineral taaffeite. This magnesium-rich beryllium oxide crystallizes in the trigonal system, in contrast to the hexagonal system of taaffeite, and is highly sought after by rare stone collectors. A 0.86 ct musgravite, identified by Raman spectroscopy, contained a particularly interesting inclusion scene consisting of numerous etch tubes (see above center image) that broke the surface of the faceted stone. With a direct source of light, these etch tubes displayed vibrant colors resulting from thin-film iridescence in the air-filled, crystallographically aligned tubes. This is the first musgravite gemstone displaying any type of optical phenomenon that anyone has examined to date.
Musgravite or magnesiotaaffeite - (chemical formula of Be(Mg, Fe, Zn)2Al6O12), is a rare oxide mineral. Its locality is the Ernabella Mission, Musgrave Ranges, South Australia for which it was named. It is a member of the taaffeite family of minerals. Its hardness is 8 to 8.5 on the Mohs scale. The closely-related Magnesiotaaffeite, which crystallizes in the hexagonal system, is known in mineralogy as Magnesiotaaffeite-2N’2S. Together, they are both parts of the Taaffeite group.
The rare gems taaffeite and musgravite have lately become more popular among collectors. Due to their similar chemical compositions and crystal structures, their main gemological properties overlap and so sophisticated measurement techniques such as quantitative chemical analysis, Raman spectroscopy, X-ray powder or single crystal diffraction are needed for their identification. A special rotating and tilting stage has been constructed to non-destructively determine the differences in diffraction pattern based on the different symmetries (trigonal and hexagonal), unit cell dimensions and space groups of taaffeite and musgravite.
Facet grade musgravite was not reported until 1993 and as of 2005, there were only eight musgravite specimens, three of which were identified by Murray Burford, a Canadian gemologist. The mineral has since turned up in Greenland, Madagascar, Antarctica, Sri Lanka, and Tanzania.
Credits: Wikipedia.com, https://www.diamondrocks.co.uk, www.gia.com, http://www.musgravite.com, http://bjordangemstones.blogspot.com, mindat.org
Sound waves reveal diamond cache deep in Earth’s interior
Study finds that 1–2% of Earth’s oldest mantle rocks are made from diamond ...
Jennifer Chu | MIT News Office
July 16, 2018
There may be more than a quadrillion tons of diamond hidden in the Earth’s interior, according to a new study from MIT and other universities. But the new results are unlikely to set off a diamond rush. The scientists estimate the precious minerals are buried more than 100 miles below the surface, far deeper than any drilling expedition has ever reached.
The ultradeep cache may be scattered within cratonic roots — the oldest and most immovable sections of rock that lie beneath the center of most continental tectonic plates. Shaped like inverted mountains, cratons can stretch as deep as 200 miles through the Earth’s crust and into its mantle; geologists refer to their deepest sections as “roots.”
In the new study, scientists estimate that cratonic roots may contain 1 to 2 percent diamond. Considering the total volume of cratonic roots in the Earth, the team figures that about a quadrillion tons of diamond are scattered within these ancient rocks, 90 to 150 miles below the surface.
“This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it’s relatively common,” says Ulrich Faul, a research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “We can’t get at them, but still, there is much more diamond there than we have ever thought before.”
Faul’s co-authors include scientists from the University of California at Santa Barbara, the Institut de Physique du Globe de Paris, the University of California at Berkeley, Ecole Polytechnique, the Carnegie Institution of Washington, Harvard University, the University of Science and Technology of China, the University of Bayreuth, the University of Melbourne, and University College London.
A Sound Glitch!
Faul and his colleagues came to their conclusion after puzzling over an anomaly in seismic data. For the past few decades, agencies such as the United States Geological Survey have kept global records of seismic activity — essentially, sound waves traveling through the Earth that are triggered by earthquakes, tsunamis, explosions, and other ground-shaking sources. Seismic receivers around the world pick up sound waves from such sources, at various speeds and intensities, which seismologists can use to determine where, for example, an earthquake originated.
Scientists can also use this seismic data to construct an image of what the Earth’s interior might look like. Sound waves move at various speeds through the Earth, depending on the temperature, density, and composition of the rocks through which they travel. Scientists have used this relationship between seismic velocity and rock composition to estimate the types of rocks that make up the Earth’s crust and parts of the upper mantle, also known as the lithosphere.
However, in using seismic data to map the Earth’s interior, scientists have been unable to explain a curious anomaly: Sound waves tend to speed up significantly when passing through the roots of ancient cratons. Cratons are known to be colder and less dense than the surrounding mantle, which would in turn yield slightly faster sound waves, but not quite as fast as what has been measured.
“The velocities that are measured are faster than what we think we can reproduce with reasonable assumptions about what is there,” Faul says. “Then we have to say, ‘There is a problem.’ That’s how this project started.”
Diamonds in the Deep
The team aimed to identify the composition of cratonic roots that might explain the spikes in seismic speeds. To do this, seismologists on the team first used seismic data from the USGS and other sources to generate a three-dimensional model of the velocities of seismic waves traveling through the Earth’s major cratons.
Next, Faul and others, who in the past have measured sound speeds through many different types of minerals in the laboratory, used this knowledge to assemble virtual rocks, made from various combinations of minerals. Then the team calculated how fast sound waves would travel through each virtual rock, and found only one type of rock that produced the same velocities as what the seismologists measured: one that contains 1 to 2 percent diamond, in addition to peridotite (the predominant rock type of the Earth’s upper mantle) and minor amounts of eclogite (representing subducted oceanic crust). This scenario represents at least 1,000 times more diamond than people had previously expected.
“Diamond in many ways is special,” Faul says. “One of its special properties is, the sound velocity in diamond is more than twice as fast as in the dominant mineral in upper mantle rocks, olivine.”
The researchers found that a rock composition of 1 to 2 percent diamond would be just enough to produce the higher sound velocities that the seismologists measured. This small fraction of diamond would also not change the overall density of a craton, which is naturally less dense than the surrounding mantle.
“They are like pieces of wood, floating on water,” Faul says. “Cratons are a tiny bit less dense than their surroundings, so they don’t get subducted back into the Earth but stay floating on the surface. This is how they preserve the oldest rocks. So we found that you just need 1 to 2 percent diamond for cratons to be stable and not sink.”
In a way, Faul says cratonic roots made partly of diamond makes sense. Diamonds are forged in the high-pressure, high-temperature environment of the deep Earth and only make it close to the surface through volcanic eruptions that occur every few tens of millions of years. These eruptions carve out geologic “pipes” made of a type of rock called kimberlite (named after the town of Kimberley, South Africa, where the first diamonds in this type of rock were found). Diamond, along with magma from deep in the Earth, can spew out through kimberlite pipes, onto the surface of the Earth.
For the most part, kimberlite pipes have been found at the edges of cratonic roots, such as in certain parts of Canada, Siberia, Australia, and South Africa. It would make sense, then, that cratonic roots should contain some diamond in their makeup.
“It’s circumstantial evidence, but we’ve pieced it all together,” Faul says. “We went through all the different possibilities, from every angle, and this is the only one that’s left as a reasonable explanation.”
This research was supported, in part, by the National Science Foundation.
Need another reason to travel to Hawaii? How about tiny gemstones falling out of the sky? This is just another reason why Hawaii is a magical and unique place unlike any other on Earth. So for this month we are going to focus on olivine, a mineral that makes up vast amounts of the Earth's subsurface. It comes in a number of varieties, but it is commonly known as Peridot when used as a gemstone.
Hawaii's Kilauea volcano has been fiercely erupting for well over a month and residents are finding little green gems that have fallen out of the sky during Kilauea's eruption. The green gems are olivine crystals, a common mineral found in Hawaii's lava. At jewelry quality, the mineral is called peridot. As the volcano erupts, it blasts apart molten lava, allowing for green olivine minerals to be separated from the rest of the melt and fall as tiny gemstones.
There are several places in Hawaii that the beaches are a green color due to the high concentrations of olivine that has weathered out of the mafic lava (basalt). In fact, olivine is one of the most common minerals below Earth's surface but it is quite hard to find it separated from the parent rock and even harder to find it of gem quality.
Olivine is so common that experts estimate over 50 percent of Earth's upper mantle is composed of olivine or variations of the mineral. While it is a common mineral, little crystals of olivine falling out of the sky are quite unusual.
"Friends of mine live in Hawaii, right next to the area impacted by the most recent lava flows. In the midst of the destruction nearby & stress of the unknown, they woke up to this - tiny pieces of olivine all over the ground. It is literally
raining gems. Nature is truly amazing." — Erin Jordan (@ErinJordan_WX) June 11, 2018
Hawaii's volcanoes are hotspots, where the mantle magma continually upwells and burns a hole through Earth's oceanic crust. Oceanic crust, in composition, is very similar to what we would find in the upper mantle with high olivine concentrations. This means the true composition of the upper mantle is not significantly altered when erupted on Hawaii's surface as basalt. The reason we get a variety of other rocks on continents is largely due to magma traveling through the varied geology that underlies each continent. This adds and removes chemicals/minerals and alters the original composition of the magma from basalt to a unique blend of minerals.
Olivine can be found throughout the island, typically as a mineral within the basalt rock. However, from the continuous pounding of waves or construction, the minerals can be broken away from the surrounding basalt. Typically, olivine erupts with the calm oozing of basalt lava on Hawaii, locking it away within the rock fabric. However, in this instance the sudden ejection of lava into the air rapidly cools and separates the melt, allowing the olivine to lithify as a separate crystal.
While it may seem like a perfect excuse to buy a ticket to Hawaii and collect some gems, please note that removing rocks, minerals, or sand from Hawaii is not only in poor taste, it is illegal. So please make sure to enjoy them in the moment, take photos, but leave the beauty on the island for others to enjoy in the future.
Only time will tell how the uniquely prolonged eruption plays out and what next will dazzle us from Hawaii's Kilauea volcano.
Kilauea Volcano Eruption
Papakolea Green Sand Beach
Trillion Cut Peridot
Peridot Rough Crystal
Kilauea's Little Olivine Gems
A colorized image, enlarged 100,000 times, shows an ultra-thin layer of molybdenum disulfide stretched over the peaks and valleys of part of an electronic device.
Nature loves crystals. Salt, snowflakes and quartz are three examples of crystals – materials characterized by the lattice-like arrangement of their atoms and molecules.
Industry loves crystals, too. Electronics are based on a special family of crystals known as semiconductors, most famously silicon. To make semiconductors useful, engineers must tweak their crystalline lattice in subtle ways to start and stop the flow of electrons. Semiconductor engineers must know precisely how much energy it takes to move electrons in a crystal lattice.
This energy measure is the band gap. Semiconductor materials such as silicon, gallium arsenide and germanium each have a band gap unique to their crystalline lattice. This energy measure helps determine which material is best for which electronic task.
Now an interdisciplinary team at Stanford has made a semiconductor crystal with a variable band gap. Among other potential uses, this variable semiconductor could lead to solar cells that absorb more energy from the sun by being sensitive to a broader spectrum of light. The material they used is in itself not new. They chose molybdenum disulfide, or MoS2, a rocky crystal like quartz, that is refined for use as a catalyst, a coating for turning things black and as a lubricant.
Molybdenum disulfide is what scientists call a monolayer: A molybdenum atom links to two sulfurs in a triangular lattice that repeats sideways like a sheet of paper. The rock found in nature consists of many such monolayers stacked like a ream of paper. Each MoS2 monolayer has semiconductor potential.
“From a mechanical engineering standpoint, monolayer MoS2 is fascinating because its lattice can be greatly stretched without breaking,” said Zheng, an associate professor. By stretching it to different tolerances, different electrical properties can be engineering into the monolayers.
Based on a 2012 MIT theoretical paper, the team at Stanford created a silicon landscape that they could sculpt in exquisite detail and then bathed the nanoscale hills and valleys in a monolayer of molybdenum disulfide.
By stretching the lattice, the Stanford researchers were able to shift the atoms in the monolayer. Those shifts changed the energy required to move electrons around. Stretching the monolayer made MoS2 something new to science and potentially useful in electronics: an artificial crystal with a variable electronic conduction.
Molybdenum disulfide is an inorganic compound composed of molybdenum and sulfur. Its chemical formula is MoS2. The compound is classified as a transition metal dichalcogenide. It is a silvery black solid that occurs as the mineral molybdenite, the principal ore for molybdenum. MoS2 is relatively unreactive. In appearance and feel, molybdenum disulfide is similar to graphite. It is widely used as a dry lubricant because of its low friction and robustness. Bulk MoS2 is a diamagnetic, indirect bandgap semiconductor similar to silicon.
Molybdenum Disulfide Mineral Sample
Molybdenum Disulfide Chemical Model - 2 Monolayers
Image Credits: Electron micrograph photo - Hong Li,
Evolve or Parish: Well, not really a mineral or a fossil, but could prompt some good conversation with the kids. Definitely geared towards family fun and maybe - dare we say it? - learning a bit as well. It may not be the most friendly game name that we've seen, but it does teach a bit about past creatures and geologic time. You can download the game in the high resolution jpeg file and print it out on your printer and the rules as well.
Evolve or Perish is a board game – not from the makers of Monopoly, but from ETE, the Evolution of the Terrestrial Ecosystems Program, at the Smithsonian National Museum of Natural History. Paleontologists Cindy Looy and Ivo Duijnstee asked illustrator Hannah Bonner to work with them to create it.
As long as you have a printer, a die (the singular of dice :-) and someone to play with, you’re all set. Enjoy!
Above: click on the PDF icon to download the rules for the game.
Left: Click on the game board to download a version to print out.
This Video Offering is About one of the Best Preserved Dinosaur Fossils Ever Discovered: Known as a Nodosaur, this 110 million-year-old, armored plant-eater is the best preserved fossil of its kind ever found.
That Monday had started like any other at the Millennium Mine, a vast pit some 17 miles north of Fort McMurray, Alberta, operated by energy company Suncor. Hour after hour Funk’s towering excavator gobbled its way down to sands laced with bitumen—the transmogrified remains of marine plants and creatures that lived and died more than 110 million years ago. It was the only ancient life he regularly saw. In 12 years of digging he had stumbled across fossilized wood and the occasional petrified tree stump, but never the remains of an animal—and certainly no dinosaurs.
Sources: Wikipedia, Mindat.org,
Covellite (also known as covelline) is a rare copper sulfide mineral with the formula CuS. This indigo blue mineral is ubiquitous in copper ores, it is found in limited abundance and is not an important ore of copper itself, although it is well known to mineral collectors. The mineral is associated with chalcocite in zones of secondary enrichment (supergene) of copper sulfide deposits. Commonly found with and as coatings on chalcocite, chalcopyrite, bornite, enargite, pyrite, and other sulfides, it often occurs as pseudomorphic replacements after other minerals. Despite the very rare occurrence as a volcanic sublimate, the initial description was at Mount Vesuvius by Nicola Covelli (1790–1829).
Covellite is quite beautiful as a natural specimen exhibiting Indigo-blue or darker, inclining towards blue-black, often iridescent with purplish, deep red, and brassy-yellow reflections in its color spectrum. In addition to its own beauty, it is often found with pyrite and other sulfides that can make stunning specimens.
Covellite is commonly found as a secondary copper mineral in deposits. It is rarely a primary mineral in copper deposits, and is even less likely to be found as a volcanic sublimate. Covellite is known to form in weathering environments near the surface in deposits where copper is found with sulfides. As a primary mineral, the formation of covellite is restricted to hydrothermal
Covellite's occurrence is widespread in the United States. In Silver Bow County, Montana, covellite has been found in veins at depths of 1,150 m (3,770 ft), as the primary mineral. Covellite formed as clusters in these veins reaching one meter across in Leonard mines, Montana. As a secondary mineral, covellite also forms as descending surface water in enrichment zone oxides and redeposits covellite on some sulfides (pyrite and chalcopyrite). Locally, findings of covellite have been discovered in salt domes and at the McCellan copper mine in Foard County, Texas. An unusual occurrence of covellite was found replacing organic debris in the red beds of New Mexico.
It has also been reported from the Calabona mine, Alghero, Sardinia; at Bor, Serbia; from Leogang, Salzburg, Austria; at Dillenburg, Hesse and Sangerhausen, Saxony, Germany; from Kedabek, Caucasus Mountains, Russia and in the Bou-Skour mine, Bou Azzer district, Morocco.
Covellite was the first identified naturally occurring superconductor. The framework of CuS3/CuS2 allow for an electron excess that facilitate superconduction during particular states, with exceptionally low thermal loss. Material science is now aware of several of covellite's favorable properties and several researchers are intent on synthesizing covellite. It has been experimentally demonstrated that the presence of ammonium vanadates is important in the solid state transformation of other copper sulfides to covellite crystals.
As a gemstone or in jewelry applications, covellite is a poor choice because of its low hardness (1.5-2.0 Mols) but it is sometimes made into cabochons or more rarely it is faceted because of it's beautiful peacock blue colors. Covellite is often found with pyrite and chalcopyrite which can add to its beauty in cabs. These polished stones are often protected with a jewelers sealant that is much harder than the covellite to protect it from easily being scratched or broken.
For February we are going to take a short trip down memory lane to discover Michigan Meteorites. With the recent hit that Michigan took, we thought it would be very timely to explore the known history of Meteorite impacts in the Great Lakes State. For those of you who are unfamiliar with what a meteor is, it's a piece of an asteroid, comet or other planet that has been been captured by Earth's gravity and falls through the sky to be found.
Michigan is No Stranger to Meteorites
Credit to Mark Torregrossa |
Michigan has had at least 10 meteorites found on its soil. Historical records show where the meteorites were found and how much they weighed. Meteorites are named after the location they are found. It the case like last week, the meteorite will likely be named after where the biggest piece was found. The most recent meteorite hasn't been named yet.
Meteorites are also considered a "find" or a "fall." A fall is a meteorite that is found right after falling, and the location can be pegged to a certain falling meteor. The most recent meteorite will be classified a fall because we saw it one night and found pieces in the following days. Other meteorites are classified as finds. The typical found meteorite was picked up in a farm field as ground was being cleared in Michigan.
Michigan's Known Meteorites
In this graphic are the locations of meteorites found or seen falling in Michigan. Information is derived from 'Meteorites of Michigan', a MSU Abrams Planetarium publication, and John Zawiskie, curator of Earth and Life Sciences at Cranbrook Institute of Science, Bloomfield Hills, MI.
Image Credit: mlive
Grand Rapids - 112 Lb. Meteorite
According to "Meteorites of Michigan" by MSU's Abrams Planetarium, the Grand Rapids meteorite was the biggest and the first significant meteorite found in Michigan. It was found in 1883, three feet underground. The meteorite weighed 112.4 pounds. It was composed of 89 percent iron, 10 percent nickel and some traces of other elements.
Allegan - 70 Lb. Meteorite
A 70 pound meteorite fell near the village of Allegan on July 10, 1889. It fell at 8 a.m. and was wintessed by Michiganders. One account says a child and his siblings were weeding a potato field when they heard it fall. At the time, people thought it was 20 feet in the ground, but it was only 1.5 feet in the ground. They were told to wait until the next day to dig it out because it would be too hot.
Reed City - 44 Lb. Meteorite
The Reed City meteorite weighed almost 44 pounds and was found in a farm field. Pieces of the meteorite are displayed at Michigan State University, Chicago Natural History Museum and several other museums.
Seneca - 4.2 Lb. Meteorite
In 1923 a meteorite was found in a corn field in Seneca township. This meteorite was traced back to 1903 using personal journals written on the farm. The meteorite was tested for composition and was mostly iron and nickel with trace amounts of cobalt, copper, sulphur and phosphorus.
Worden Meteorite - Only Damaging Sky Stone
In 1997 a meteorite actually hit a garage and car in Worden, MI. The meteorite was small in size, but blasted right through the roof of a garage. A model of this meteorite and damage to the car are on display at Cranbrook Institute of Science. The meteorite in Worden was traveling so fast it made a clean hole in the garage roof. The hole mirrored the shape of the meteorite. John Zawiskie, of the Cranbrook Institute of Science, compared the hole to cartoons when a character goes through a wall and leaves an exact body print.
Iron River - 3.1 Lb. Meteorite
According to "Meteorites of Michigan," the composition brought scientists to date the meteorite at 290 million years old to 430 million years old. They determined the meteorite originated from a cosmic collision over 300 million years ago.
Coleman - 1.1 Lb. Meteorite
The Coleman meteorite was only 1.1 pounds and was found in 1994. This meteorite is classified a "fall" because the meteorite was found just after a fireball hit the ground.
A Michigan meteorite caught on camera in the Michigan thumb area.
Images of the new Michigan Meteorite
The Recent Michigan Chondrite Meteorite
credit: Mark Hicks, The Detroit News
On Tuesday, January 16th at 8:15p.m., a six foot wide meteor broke apart over the earth at about 20 miles high. The Majority of the fragments seem to have landed in Hamburg Township. Numerous people either saw the meteor fall, saw the flash of light, felt the tremors or heard a loud explosion like sound that evening. “The asteroid hit the atmosphere, moving about 28,000 miles per hour, broke apart over southeast Michigan and scattered meteorites on the ground,’’ said Bill Cooke, lead of the NASA meteoroid environment office.
The first fragments were located Thursday by professional meteorite hunters Larry Atkins and Robert Ward of Arizona, according to the American Meteor Society. Ward used seismic data, radar information and eye witnesses to track down the pieces he was able to find. Those remnants must undergo analysis at a laboratory accredited to certify meteorites, such as Chicago’s Field Museum. Hunters had started combing southeast Michigan for the pieces the day after a NASA camera spotted the meteor over Ohio.
The new meteor has already been classified as a chondrite: A chondrite has a stony composition that contains small granules of minerals (usually silicate minerals). Chondrites are physically and chemically the most primitive meteorites in the solar system. Because the meteor burned up during it's path through the atmosphere, there is a black fusion crust on some of the samples found so far. It takes a ton of patience to find any fragments and the recent snow melt will make it more difficult to find more pieces as the first pieces found were located on top to the snow which helped them to stand out.
Meanwhile, Darryl Pitt, a curator at Macovich Collection of Meteorites in New York and meteorite consultant to the Christie’s auction house, is offering $20,000 to the first person willing to sell a recovered chunk weighing at least 2.2 pounds (1 kilogram). “I want to motivate more people to look,” Pitt, a Michigan native, said Thursday night. “If you take every meteorite known to exist, take the total weight, they still weigh less than the world’s annual output of gold. Meteorites are extraordinarily rare and the world is just coming to terms with how special they are.”
Those heading out to net the nuggets should beware!
Federal law says meteorites belong to the owners of the property where they land. Testing must determine whether the find qualifies as one, and even if that’s the case, “no meteorite is worth millions of dollars,” said Bill Cooke, who leads NASA’s meteoroid environment office in Alabama. “Meteorites, like gold, are prized according to type and weight.”
Figures can vary depending on circumstances, including the market and collectors’ interest, but prices for the first found and certified pieces could start at $100 per gram if more examples are not found and it remains rare. Even so, scientists seek the rocks to learn more about the phenomenon. Every meteorite is a special prize of science and the solar system. The monetary value is secondary.” That’s why Atkins and his team plan to keep searching for more artifacts. “These rocks are virgin materials from the building blocks of our solar system,” he said. “When you’re holding a meteorite, you’re holding something. It’s not just a rock.”
All meteorite hunters need to ask permission before entering any private property.
This months featured mineral is one of those that has a mysterious name. It is one of the first geodes that sparked many people to start collecting minerals and learning how crystals form.
The name Septarian is derived from the Latin name, Septem, meaning seven. This relates to the fact that the mud balls cracked with 7 points in every direction, thereby creating the beautiful design.
Septarians were formed during the Cretaceous period, 50 to 70 million years ago when the Gulf of Mexico reached what is now Southern Utah. Decomposing sea life killed by volcanic eruptions, had a chemical attraction for the sediment around them, forming mud balls. As the ocean receded, the balls were left to dry and crack. Because of their bentonite content they also shrank at the same time trapping the cracks inside. As decomposed calcite from the shells was carried down into the cracks in the mud balls, calcite crystals formed. A thin wall of calcite was transformed into aragonite separating the bentonite heavy clay exteriors from the calcite centers. Because of this, the nodules are called Septarians.
Septarians are composed of Calcite (The Yellow Centers), Aragonite (The Brown Lines) and the Outer Grey Rock is basically Limestone. Occasionally the fossil or some of the fossils which started the formation of the rock is noticeable in the rock.
Septarian is a special type of concretion. Concretions are masses of mineral matter formed when minerals in water are deposited about a nucleus (such as a leaf or shell or other particle) forming a rounded mass whose composition or cement is usually different from the surrounding rock. This can occur at the time of deposition, shortly thereafter, or after the sediment has hardened.
Generally, concretions are harder than the rocks around them; therefore, over time the concretions can weather out of the surrounding rocks. Concretions in Kansas are formed from any of a number of minerals, including calcite, limonite, barite, pyrite, or silica. They vary widely in shape and size, with the huge spherical concretions at Rock City in Ottawa County and Mushroom Rock State Park in Ellsworth County measuring up to 27 feet in diameter.
When the concretion is exposed to weathering, the softer parts between the calcite-filled cracks are eroded and the cracks extend above the surface of the concretion, like ridges or little walls.
These concretions are actually pseudo-fossils (think "fossilized" ripple marks, raindrop hits, etc...) in this case what you have are "fossilized" mud cracks. These formed when the lake bed dried out. As the mud of the lake bottom dried it contracted and voids formed. The lake bed was subsequently covered with new lake and the older one was buried. The water from the new lake seeped down through the sedimentary rock of the old lake and picked up trace amounts of calcium in passing. when the water entered the voids it would pool and the calcium would deposit out as aragonite and calcite. Most collectors label their Septarian specimens as "Septarian nodule", since the piece is composed of multiple minerals.
These nodules are often large and have interesting calcite crystal chambers. The colorful golden yellows and aragonite deep browns will contrast with the fossilized clay matrix creating artistic designs. As a result, Septarians are carved into spheres, hearts, bookends, animals and sometimes complex sculptures. See some of the the examples below:
Septarian Slab with Exposed Calcite Chamber
Septarian Carved Face
Egg with Calcite Pocket
Septarian Skull Sculpture
GROW YOUR OWN BISMUTH CRYSTALS
Bismuth has a low melting point (271°C or 520°F), so it is easy to melt over high cooking heating. You are going to grow the crystals by melting the bismuth in a metal or ceramic 'pot' (which will have a higher melting point than the bismuth). Bismuth is non-toxic, at least, it is not bio accumulative so you would need to consume a whole lot at one time to have issue. The bismuth compound bismuth-subsalicylate is the active ingredient in Pepto Bismol. It is the most highly diamagnetic element known, and is only slightly radioactive with a half life of approximately 19,000,000,000,000,000,000 years.
To do this you will need a hammer, 2 to 3 appropriate pots or containers to melt the bismuth in, some really good oven mitts, some tongs or pliers, and of course some bismuth metal. The more pure the better and easier this process is. We recommend getting it at 99.99% purity if possible. You will also need a hotplate or safe stove to use. DO NOT USE your kitchen appliances or pots you cook with! We would also recommend eye protection and a good apron.
You have a few options for obtaining bismuth. You can use non-lead fishing sinkers (for example, Eagle Claw makes non-lead sinkers using bismuth), you can use non-lead ammunition (the shot will say it is made from bismuth on the label), or you can buy bismuth metal. The quality of crystals you obtain depends in part on the purity of the metal, so make sure you are using bismuth and not an alloy. One way to be certain of the purity is to remelt a crystal of bismuth. It can be used over and over again. You can also purchase bismuth at Amazon, eBay or a number of element collector sites on the web like Roto Metals (http://www.rotometals.com). For the best result, purchase 4 to 5 pounds of bismuth. Its not really a lot because bismuth is very heavy like lead.
NOTE: As much fun and pretty as these crystals may be please be aware that this is metal. Melting metals will give off fumes; try to avoid breathing in those fumes for health reasons. For complete details on bismuth and its' properties please read the Material Safety Data Sheet (MSDS) found here: http://www.sciencelab.com/msds.php?msdsId=9927101
Separate the pure bismuth from its impurities, allow the bismuth to crystallize, and pour away the remaining liquid bismuth from the crystals before it freezes around the crystals. None of this is difficult, but it takes some practice to get the cooling time just right. Don't worry—if your bismuth freezes you can remelt it and try again. Here are the steps in detail:
Place the bismuth in one of your metal 'dishes' and heat it over high heat until it melts. The smaller the pan the better, as the deeper the pool of bismuth will grow more interesting crystals. It's a good idea to wear the mitts since you are producing a molten metal, which is not going to do you any favors if it splashes onto your skin. You'll see a skin on the surface of the bismuth, which is normal.
Preheat the other metal container to the same as the first pot. Carefully pour the melted bismuth into the heated clean container. You want to pour the clean bismuth out from under the gray skin, which may contain impurities which would negatively affect your crystals.
Set the clean bismuth in its new container on a heat-insulated surface (e.g., set the container back on the burner, but turn the power off). The cooling rate of the bismuth affects the size and structure of the resulting crystals, so you can play with this factor. Generally, slower cooling produces larger crystals. You do not want to cool the bismuth until it is solid!
When the bismuth has started to solidify, you want to pour the remaining liquid bismuth away from the solid crystals. This happens after about 30 seconds of cooling. Wearing oven mitts, gently shake the container again to check and see if the bismuth is becoming solid. (This should appear to look like very little rippling when the container is shaken.) Quickly pour the liquid bismuth into the first container that was used. There should be bismuth crystals in the second container.
Once the crystals have cooled, you can snap them out of the metal container. If you are not satisfied with the appearance of your crystals, remelt and cool the metal until it is just right.
Watch these two movies to get a better idea of the whole process:
Michigan beaches are some of the best in the world. That squeaky clean sand between your toes, beautiful fresh water beaches and so many interesting and colorful beach stones. This month we went vintage, picking up an old Michigan Department of Conservation flyer on the subject. Please download the higher resolution file to keep as a reference for looking them up next time you're enjoying the Great Lake State's shark-free waters.
Michigan Beach Stones
Text by Robert W. Kelly and sponsored by the Michigan Department of Conservation (older name for the DNR)
Our Great Lakes Shorelines are Treasure-laden with a host of truly fascinating gem materials-not only hard-to-find agates, but also easy-to-find chert, jasper, granite, quartz, and basalt. Though more plentiful around Lake Superior, the common varieties may be found most anywhere. No special training is needed for rock collecting. Just look for colors and patterns that please you. You're the judge. It's as simple as that. The variety of stones is infinite. Seldom are two precisely alike, so giving them names is also difficult. Unlike plants and animals, classes of stone grade one into another. Divisions are purely arbitrary based upon subtle differences in chemistry and texture. Sometimes, identity is difficult to establish, even in the laboratory!
One note about beachcombing along Michigan's Great Lakes: To walk on the exposed strip of dry beach, you should obtain the consent of the property owner. His rights extend to the edge of the water regardless of water level fluctuations. Permission is not required, however, if you wade in the water, just off the beach. The submerged bottom lands of the Great Lakes are public, owned by all of us together. Now, turn the page and see some of the beautiful stones awaiting you on our beaches. The specimens are reproduced here relative to their true size. Color will vary from monitor to monitor. Photography is by John R. Byerlay and Robert W. Kelley of the Geological Survey Division, Illustration is by Jim Campbell, and the specimens.
Descriptions of the Stones shown in the Color Picture
1. AMYGDALOID – (Greek: "almond") Pebbles of basalt, or lava, with almond-shaped cavities created by gas bubbles trapped beneath the crust of a once molten rock flow. Green "amygdules" are chrysocolla: red, analcite. Note copper amygdules in pebble nearest upper left corner.
2. NATIVE COPPER – Michigan's "honor mineral." Specimens found in old mine waste piles usually have a green patina coating; when polished the bright copper color emerges.
3. NATIVE SILVER – Lake Superior copper is noted for its silver content that imparts "superior" qualities for many uses. Hammered nuggets of inter-mixed copper and silver are called half-breeds.
4. LAKE SUPERIOR AGATES – Typical beach specimens. Besides their inherent hardness and fine luster, concentric banding is a definite clue to the identity of two of these specimens. The specimen on the right, however, might easily go unnoticed.
5. LAKE SUPERIOR AGATES – A string of tumbled round agates of the size most commonly found.
6. LAKE SUPERIOR AGATES – Cut and polished gem stones collected at various beaches from Ontonagon to Sault Ste. Marie.
7. HONEYCOMB CORAL – the original limey skeleton of this fossil has been replaced by silica (quartz).
8. JACOBSVILLE SANDSTONE – not considered a lapidary material, but sometimes weathering processes cement the grains into a compact mass that takes a fairly good polish.
9. PREHNITE – a member of the zeolite mineral group, which also includes thomsonite, chlorastrolite, and analcite, common to the Copper Country. See the minute flecks of copper?
10. BRECCIA – (Italian: stone fragments)- Angular pieces of basalt fragmented in a zone of violent rock breakage and re-cemented with other minerals, often quartz or calcite.
11. JASPILITE – a specimen of iron formation in which the usual red iron oxide coloring has been weathered to ochre-colored limonite.
12. CONGLOMERATE – an aggregation or "conglomeration" of rounded pebbles cemented together by other mineral matter.
13. RHYOLITE – red to brown fine-grained type of igneous rock.
14. QUARTZ – with green epidote and red jasper.
15. QUARTZ – with red jasper.
16. EPIDOTE – in basalt.
17. BRECCIA – Fragments of basalt cemented by milky quartz with traces of red jasper.
18. EPIDOTE – in basalt.
19. BRECCIA – Fragments of basalt cemented by milky quartz with traces of green epidote.
20. FINE-GRAINED GRANITE – contains small interlocked grains of clear quartz and flesh-colored feldspar.
21. JASPILITE – Interbanded red jasper and grey hematite. The ever-increasing production of iron from occurrences of this ore is a vital factor in Michigan's economy.
22. PETOSKEY STONE – fossil colony coral and Michigan's official state stone.
23. RAW BEACH STONES – a collection of various hard unpolished pebbles, typical of Lake Superior shores, but also found elsewhere to a lesser extent. True cherts are usually white, pale brown, brownish yellow, red grey, sometimes black, and occasionally green. In all cases, however, they consist of a dense, non-crystalline water-deposited form of silica that takes an exceedingly high polish. Colors are the result of other mineral impurities: iron oxide imparts the red color; green pebbles (basalts) are colored by epidote; glassy white to grey stones with frosted surfaces are usually vein quartz, a crystalline variety of silica.
24. THOMSONITE – Exquisite shades of pink and green with a radiant fibrous structure.
25. CHLORASTROLITE – the famous Michigan Lake Superior official gemstone, "greenstone".
26. TUMBLED BEACH STONES – Same as in group No. 23, except the inherent beauty of their colors and textures has been enhanced by tumbling.
27. RHYOLITE – A fine-grained igneous rock shaped into a convex gem form known as a cabochon. The group of four banded reddish brown pebbles immediately beneath are also rhyolite.
28. CHERT – with small orbs of red jasper.
29. CHERT – just chert, but most unusual and pleasing gem specimens.
30. DATOLITE – often very colorful, and though not as hard as either agate or chert, takes a superb polish because of its very dense texture. Unusual, too, because it contains the element boron. Rarely occurs on beaches, but the two yellow pebbles were picked up on a Keweenaw beach fifty paces apart and their mates!
Rocks and Minerals of Michigan. Discusses stones, rocks, minerals, and mineral resources-where found and how to identify. Collecting Minerals in Michigan. Basic suggestions for the beginning hobbyist, free. For both these, write Publications Room, Michigan Dept. of Conservation, Lansing 26, Michigan. Field Guide to Rocks and Minerals, universal pocket volume, Houghton Mifflin. Gemstones of North America, a comprehensive treatise on mineralogy and occurrence of stone deposits. Van Nostrand. Rocks and Minerals, "Golden Nature Guide" series, Simon & Schuster, paper-covered. 1001 Questions Answered About the Mineral Kingdom, "1001 Questions Answered" series, Grosset & Dunlop, paper-covered.
Earth Science, Gems & Minerals, Lapidary Journal, and Rocks and Minerals.
U.S. Geological Survey topographic quadrangle maps are available from Geological Survey Division, Individual county maps showing location of State and Federal lands available for public recreation are distributed at Department facilities throughout Michigan and may also be obtained from the Publications Room.
Michigan College of Mining and Technology, Houghton. Cranbrook Institute of Science, Bloomfield Hills. Fort Wilkins State Park, Copper Harbor.