Category: Mineral of the Month

Bumblebee Jasper is a soft (Mohs hardness of 5) and porous sedimentary rock that is bright yellow-orange, gray, and black.  Although Bumblebee jasper appears to be manipulated or man-made, specimens with their brilliant colors are natural, enhanced only through cutting and polishing. Bumblebee jasper is known locally as batu badar belerang. This roughly translates to “coal becoming sulfur.” It was named Bumblebee jasper by an American rock and mineral enthusiast who found the stone while working in Indonesia during the 1990s.

Bumblebee Jasper is not a true jasper, nor is it a single mineral.  Many colorful stones used for decorative purposes are given trade names.  Jasper is always a popular option because it is a mineral term with which most people are familiar. Jasper is associated with quartz (silica), and there is no quartz in Bumblebee stone. This rock is instead a rare limestone, primarily composed of radially grown fibrous calcite and volcanic ash.  Its white-gray color is calcite, while the black layers are pyrite (manganese oxide). Some people mistakenly report that the yellow-orange color is sulfur.  While the rock does contain traces of sulfur, the yellow-orange color has been lab-verified to be realgar.  The same report confirms a minuscule quantity of arsenic. Bumblebee Jasper is safe to wear but should be kept away from small children who may want to put it in their mouth. Any potential danger comes from inhaling its dust or microscopic fibers.  Lapidary cutting and polishing this material must be done with extreme caution and appropriate breathing protection must be used.

The only known deposits are found near Mount Papandayan, an active subduction-zone stratovolcano in West Java, Indonesia. The reported source location initially confused geologists because it is extremely rare to find limestone close to a volcano.  This rock, which formed during the upper Cenozoic era, is difficult to find. The deposits are hidden in the jungle and primarily mined using basic hand tools.  At least one of the mines can only be reached by hiking to the area on foot. Bumblebee jasper forms around fumaroles, which are cracks in the Earth where volcanic steam and gas escape without any accompanying liquids or solids. During the rainy season in Indonesia, fumaroles turn into boiling mud pools. Due to its popularity, huge amounts of Bumblebee jasper have been mined, leaving very little fine-grade material left to find.

Metaphysical experts suggest that Bumblebee jasper has an encouraging and empowering energy that helps.

CITES:
https://moonrisecrystals.com/bumblebee-jasper-meaning/
https://www.stonemania.co.uk/crystals/b/bumblebee-jasper
https://commons.wikimedia.org/wiki/File:N%C3%A1mafjall_in_summer_2009_(2).jpg
https://www.mindat.org/min-46602.html
https://commons.wikimedia.org/w/index.php?search=bumblebee+jasper&title=Special:MediaSearch&go=Go&type=image
https://www.rockyourworldgems.com/pages/about-bumblebee-jasper

In chemistry, an element is a pure substance consisting only of atoms that all have the same numbers of protons in their nuclei. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by any chemical reaction. In school we learned about elements via the Periodic Table of Elements.

There are 118 elements that have been identified and listed in the Periodic Table, 94 that occur naturally on Earth (depending on how you count them). The lightest elements are hydrogen and helium (atomic numbers 1 and 2); the heaviest is uranium (atomic number 92). The remaining 24 heavier elements, not found today on Earth, have been produced artificially. Only around 32 elements, such as silver and gold, can be found in an uncombined, relatively pure form. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. For example, air is primarily a mixture of the elements nitrogen, oxygen, and argon, but also can contain compounds including carbon dioxide and water. 

Silicon (atomic number 14) makes up 27.7% of the Earth’s crust by mass and is the second most abundant element (oxygen is the first). It does not occur uncombined in nature, but usually mixes with oxygen to form silica minerals such as quartz, amethyst, agate, flint, and opal. Pure silicon has the same crystal structure as diamond, which is made of carbon – the element that sits above silicon in the periodic table.

It is important to point out that silicon and silicone are quite different. Silicon is a naturally occurring element, number 14 on the periodic table. Silicone is a synthetic material made of silicon–oxygen polymers used for a variety of applications.

When ultrapure, silicon is a gray solid with a glossy sheen. Although it looks like a metal, silicon is classified as a metalloid – it conducts electricity only under certain conditions – making it well-suited for the electronics industry (e.g., computer chips).

The silicon images shown above and in the photos below have been purified from silicon dioxide quartz (silica). The manufacture of this silicon (which is 98% pure) occurs in two stages. The oxygen is removed to produce metallurgical grade silicon, such as the specimens shown here. It is then further refined to produce semiconductor grade silicon.

If it were not for the element silicon, there would be no agates on Earth. Thank you silicon!

CITES:

Periodic Table image: https://commons.wikimedia.org/wiki/File:Periodic_table_large.png

Silicon element: https://commons.wikimedia.org/wiki/File:Electron_shell_014_Silicon.svg

Silicon info: https://commons.wikimedia.org/wiki/File:Silicon.svg

Silicone: https://commons.wikimedia.org/wiki/File:Maryse_cuisine.JPG

Silicon computer chip: https://commons.wikimedia.org/wiki/File:VIA_Nano_E-Series_Chip_Image_-_45_Degree_(4542811524).jpg

The remaining photos on this page were taken by Karen Brzys.

Pegmatites are a variety of granite with the largest crystals in the granitic family of rocks, usually larger than a half inch (1.25 cm). Extremely large crystals have been found in pegmatites, including some over 30 feet in diameter (10 m). Pegmatites formed below the Earth’s surface at the top or along the outer edges of magma chambers, or in smaller intrusions leading out of the magma chambers. This rock developed during the final stage of crystallization within magma chambers, so it was the last rock to solidify. Like granite, most minerals in pegmatites include quartz, feldspar, and mica. Rare minerals are also found in pegmatites such as beryl (emerald and aquamarine), tourmaline, topaz, fluorite, apatite, corundum (ruby), tin, tungsten, and others. The photo above is a pegmatite boulder with large emerald crystals.

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The Crabtree Pegmatite photos shown above are from North Carolina. They have black schorl tourmaline crystals, pinkish-reddish garnet crystals, medium-gray quartz, and whitish-gray feldspar. This deposit from the Devonian period is around 400 million years old.

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The above Brazilian pegmatite specimen has large mica and feldspar crystals.

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This Colorado pegmatite has large feldspar and quartz crystals (1.4 billion years old).

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The photos above show that mineral crystals in pegmatites may not be uniform in size as they are in granite. Pegmatites usually have different zones of crystallization with a variety of mineral sizes and assemblages.

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The two photos above show pegmatites from Lake Superior beach. Both of these specimens are intermediate between granite and pegmatite.

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This cross-polarized microscopic image of a Norway pegmatite shows large mica and feldspar crystals. Field of view = .13 inches wide (3.3 mm).

Figure Cites (in order of appearance above):

–James St. John, File:Emeralds in pegmatitic granite 8 (37992559234).jpg – Wikimedia Commons.

–James St. John, https://commons.wikimedia.org/wiki/File:Garnets_and_tourmaline_in_pegmatitic_ granite_(Crabtree_Pegmatite,_Devonian;_Crabtree_Mountain,_Mitchell_County,_North_Carolina,_ USA)_1_(25144467358).jpg.

–James St. John, https://commons.wikimedia.org/wiki/File:Garnets_and_tourmaline_in_pegmatitic_ granite_(Crabtree_Pegmatite,_Devonian;_Crabtree_Mountain,_Mitchell_County,_North_Carolina,_ USA)_1_(25144467358).jpg.

–Géry Parent, https://commons.wikimedia.org/wiki/File:Mica,_feldspar.jpg.

–James St. John, https://commons.wikimedia.org/wiki/File:Graphic_granite_(runite)_(Eight_Mile_Park_ Pegmatite_District,_

Mesoproterozoic,_1.430_to_1.474_Ga;_roadcut_along_3A_Road,_north_of_Royal_Gorge_Bridge,_west_of_Canon_City,_south-Central_Colorado,_USA)_10_(48751697192).jpg.

–Karen Brzys photograph.

–Karen Brzys photograph.

–Karen Brzys photograph.

–Karen Brzys photograph.

–Jonas Börje Lundin, https://commons.wikimedia.org/wiki/File:H.ellglimmer_in_Pegmatit.jpg.

While I was on my fall trip to South Dakota to agate hunt and recover from the crazy summer, I was given a lead from a friend regarding a rock shop that had gone out of business.  I met with one of the co-owners the first time to go over the exceptionally large inventory, but we ran out of time.  I went back a few days later and bought quite a bit.  One of the boxes of specimens I purchased was Royal Aztec purple agate.  This agate was mined out in the 1960s, so it is now extremely rare and difficult to find.  It is considered one of the best seam agates ever found on Earth.  The deepness of the purple color can vary, as can the amount of banding and other structure.  One unusual thing about this agate is that if it is stored in sunlight, the deepness of the color will fade.

The agate was found in Durango, Mexico.

At the end of January, I drove from Florida to Arizona to purchase minerals for the Gitche Gumee Museum’s gift shop. I used to go to the Tucson Gem and Mineral Show every year. Now, to minimize expenses, I go every three to four years. But it is always to go to this huge show (which is actually more than 40 separate shows located all over the city)!

One of the minerals I purchased this year for the first time is a combination rock from the Democratic-Republican of the Congo (formerly Zaire). This country of more than 100 million people is in the middle of the African continent.

In the past, the museum has sold Chrysocolla and Malachite but never had I had the privilege of selling this combination rock. The green in these specimens is malachite; the blue is chrysocolla. There is also black heterogenite included in some of the specimens. These minerals are secondary-fill copper minerals that form deep underground.

Chrysocolla has a blue-green/cyan color and is a minor secondary ore of copper that formed when copper ores were altered by mineral-rich fluids
Malachite also gets its color from copper, which makes up about 58 percent of its content.

Technically, malachite is a “secondary mineral,” which means it formed when copper-rich rocks were dissolved or chemically altered by circulating fluids. Malachite’s characteristic swirling and concentric patterns are a result of this formation process. This beautiful mineral was mined in Egypt over 6,000 years ago. Not only was it used as both a gemstone and a decorative stone, but it was ground into green pigments for painting and cosmetics. Synthetic green pigments equaling the vivid color of Malachite were not developed for thousands of years until the Industrial Revolution. But if you decide to work on polishing and cutting malachite, BE CAREFUL! The copper content of the dust released from grinding malachite is toxic! Please keep the rough stone wet and wear protective respiratory gear.

Chrysocolla-Malachite is a combination of two copper-derived silicate minerals. Since these specimens contain different minerals, they are considered rocks. Minerals are consistent in their make-up; rocks contain different minerals and are not consistent in how much of each mineral they contain. An easy way to understand the difference is that rocks are like cookies: they contain different ingredients such as flour or sugar (which are like minerals). The sugar making up cookies may be the same, but other ingredients in cookies change – so cookies are not always the same!

In the case of Chrysocolla-Malachite, it is a combination of two Copper minerals.  Copper typically formed as a sulfide, which oxidized when exposed to water.  If that water also contained carbonic acid, it dissolved the copper and formed new compounds, including green malachite.  If the copper was oxidized, cyan-colored chrysocolla also may have formed.  Sometimes these two situations happened in the same spot and at the same time resulting in both chrysocolla and malachite developing next to each other and intertwining – which is what happened to form these combination rocks in the Democratic Republic of the Congo.

Syenite is a coarse-grained intrusive igneous rock formed when molten lava cooled slowly under the Earth’s surface. It has a general composition like granite.

Ultraviolet Light (UV) is light categorized between the wavelengths of 100 nm and 400 nm. These wavelengths are shorter than what humans can see.

Fluorescence is the emission of light by a substance that has absorbed light in the ultraviolet range of the spectrum and emits light in the visible spectrum. The emitted light has a longer wavelength, and therefore can be visibly seen, than the exciting invisible UV wavelength. Fluorescence happens on the atomic level. When a substance fluoresces, the electrons in the atoms reacting to the UV light get excited by the wavelength and use the energy to jump away from the nucleus to a higher electron orbit. Nuclei do not like empty electron shells, so they pull electrons back down to fill the empty slot. This movement back down releases energy, which is displayed by light in the visible spectrum.

“Yooperlites” contain a variety of sodalite with an impurity that reacts to the specific UV wavelength of 365nm. This wavelength was developed to detect cat urine, as well as for use in manufacturing processes. Fluorescent syenite has minimal fluorescence with a 395nm wavelength.

In most cases, syenite is not fluorescent. In most cases, sodalite is also not fluorescent. The suspected source of this variety of syenite that has a fluorescent form of sodalite is believed to come from central Ontario. The rock was transported to the Michigan area 8,000 to 10,000 years ago by glaciers and/or by icebergs on Lake Algonquin, a larger predecessor lake to Lake Superior. The east coast of Lake Algonquin was in the area of the fluorescent syenite deposit. Thus, once all the fluorescent syenite specimens are picked up from the Lake Superior beaches, the supply will be gone since it cannot be replenished – at least until the next glacier scrapes across the landscape. So PLEASE, if you go out to find these amazing rocks, just take a few and leave the rest for others to find.

Some people have attempted to find fluorescent syenite during daytime hours. This is almost impossible since the syenite looks very much like granite. Without the 365nm wavelength, and the darkness needed to see its effect, there is no way to identify the fluorescent component during the day.

Both granite and syenite are similar in that they are intrusive igneous rocks that formed when molten magma cooled slowly under the earth’s surface. During cooling, minerals of the same type combine to form mineral grains. The slower the cooling, the larger the mineral grains. The difference between granite and syenite is primarily due to the quantity of quartz. Granite has as one of its components more than 20 percent quartz; syenite has five percent or less. In the photos below, notice the granite on the left is “whiter” due to the quartz. Syenite is on the right with little to no white quartz.

Here are two more photos of syenite.

The search is underway to find other deposits of fluorescent syenite. One of the museum’s customers had several samples of syenite he collected on the north shore of Lake Superior. He brought some into the museum and it was not at all fluorescent. Once these glowing rocks have all been picked up from the beach (and we are almost there already), there will be people searching for a new deposit source.

*The term “Yooperlite” is a trade named by Erik Rintamaki who discovered these fluorescent rocks on the Lake Superior beach in 2017.

Lapis lazuli, or lapis for short, is a metamorphic rock with an incredible, deep blue color.  Because of its intense color, this rock is collected as a semi-precious stone.  In fact, it has been collected since around 7,000 B.C.!  The largest and most prolific Lapis mines are located in Afghanistan, but the rock is also found in Russia, Chile, Italy, Mongolia, Canada and the U.S. 

In addition to Lapis being used in jewelry, at the end of the Middle Ages the stone was exported to Europe, where it was ground into a fine powder and used to make a paint pigment called ultramarine. Ultramarine was the finest and most expensive blue used by Renaissance painters. It was often used for the robes of the Virgin Mary, and symbolized holiness and humility. It remained an extremely expensive pigment until a synthetic ultramarine was invented in 1826.

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Since lapis is a rock, it contains many different minerals.  From specimen to specimen, the exact composition, of course, varies.  The most important mineral component is lazurite (25% to 40%).  This rock can also contain calcite, sodalite, pyrite, augite, diopside, mica, hornblende, and more.  

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Lapis is often used in lapidary since it takes an excellent polish.  It is made into jewelry, carvings, boxes, mosaics, ornaments, small statues, and vases.

According to metaphysical experts, Lapis stones can help us to go deep within ourselves to discover our true purpose and destiny.  It can also help enhance self-expression and awareness.  Lapis is a universal symbol of wisdom and truth.  

CITES

https://en.wikipedia.org/wiki/Lapis_lazuli

Hannes Grobe, https://commons.wikimedia.org/wiki/File:Lapis-lazuli_hg.jpg

https://en.wikipedia.org/wiki/Ultramarine

Arpingstone, https://commons.wikimedia.org/wiki/File:Lapis.elephant.800pix.060203.jpg

fr:User:Luna04, https://commons.wikimedia.org/wiki/File:Lapis_lazuli_block.jpg

Dezidor, https://commons.wikimedia.org/wiki/File:Ermitáž_(28).jpg

Ohio flint is the official gemstone of Ohio.  It was designated the state stone in 1965.  There are ridges and other deposits throughout Ohio, but most can be found in the eastern and central parts of the state.   

Flint is a microcrystalline variety of silica (quartz).  It is very closely related to Jasper and Chert since all three are made up of extremely small round crystals of silica.  The microcrystals pack together so tightly (like BBs in a jar) causing these rocks to be opaque.  Agate is a “first cousin” variety of microcrystalline silica, but its microcrystals are fibrous in shape and are translucent.

Flint, as well as chert and some jaspers, were highly prized by Native Americans since the rocks were able to be knapped to make arrowheads, spear points, beads, and other objects.  Many Native Americans in the mid-West traveled to Ohio to collect flint.  These tribes, as well as those living in Ohio, traded flint with other tribes in a wide geographic area.

The most famous deposit of Ohio flint is found in a six square mile ridge located in eastern Licking and western Muskingum counties.  Flint from this ridge is called Vanport flint, which formed during the Pennsylvanian period between 286 and 325 million years ago. The actual deposit of flint ranges in thickness from one to twelve feet.

CITES

The Portable Antiquities Scheme/ The Trustees of the British Museum, https://commons.wikimedia.org/wiki/File:Early_Bronze_age_flint_knapped_arrow_head_(FindID_515922).jpg

Mike Streeter, http://mcrocks.com/ftr10-1/StreeterSeptember2010.html

https://statesymbolsusa.org/symbol-official-item/ohio/state-gem-gemstone/ohio-flint

Fordite, also known as Detroit agate or Motor Agate, is not actually a rock or a mineral. However, it is used in lapidary to make amazing pieces of jewelry, some of which sell for hundreds of dollars. Fordite is actually old automobile paint which has hardened into layers. Decades ago, the process used to paint automobiles was different than it is today. Back then cars were hand sprayed. The color used in the spray booth changed as the production schedule changed. Layers of the enamel paint built up on the tracks and skids on which the car frames were painted. The layers of oversprayed paint became hardened when the car bodies went into ovens to cure the paint. When the build up of paint became too thick, it was removed and discarded.

The original decades-old “Fordite” often display incredibly beautiful and complex, agate-like layers. Eventually people realized these beautiful slag-like layers were patterned like psychedelic agate and could be cut and polished into jewelry.

This spray process has now been automated with an electrostatic process that essentially magnetizes the enamels to the car bodies. This leaves little overspray. 

Some say Fordite is no longer produced in car factories, but this is not true. A customer came into my museum who has the job of cleaning the electrostatic painting equipment to remove the still accumulating layers of paint on the equipment. Although much of the modern paint layers are not as colorful as those from decades ago, there is still some jewelry-compatible material being scraped off car painting equipment. In some cases, this new material offers interesting shapes instead of bizarre colors.

Also, some people are making their own Fordite by layering and baking enamel paints in their studios.

If you have acquired a piece of Fordite jewelry, keep in mind that it is a relatively soft material. However, if you do see scratches on the surface of the Fordite, pull out your car wax and a 100 percent cotton cloth and give it a good shine!

Thanks goes to Kyle Koskinen for his photos, video, and samples. I am hoping to find room in the museum to create a “Fordite” display for the 2018 summer season.

CITES

• Rhonda, https://commons.wikimedia.org/wiki/File:2_fordite_jeweries.jpg
• Rhonda, https://commons.wikimedia.org/wiki/File:Beach_Glass_and_Fordite.jpg
• http://www.fordite.com/care.html

Septarian nodules are round concretions found in sedimentary rocks. Concretions are hard solid masses formed by the accumulation of matter within sediment. Although scientists do not agree on the details and specifics of their formation, there are several theories. One proposal suggests they formed when there was dehydration and shrinkage of clay, gel, or organic cores within sedimentary pockets. Others believe there was an expansion of gases produced by the decay of organic matter that fractured material within sedimentary pockets. One more theory is that an earthquake, compaction, or other geologic forces fractured material within sedimentary pockets. However the sedimentary material fractured, mineral-rich fluids filled in the spaces between the fractures allowing calcite, siderite, pyrite, and other minerals to crystalize and fill in the open areas within the cavity.

The most well-known septarian nodules are found in Utah. The Utah septarians developed during the Cretaceous period between 50 and 70 million years ago. At this time the Gulf of Mexico had expanded northwest into the area that is now southern Utah. Scientists believe that volcanic eruptions killed marine organisms, causing them to sink to the bottom of the shallow sea. The decomposing material chemically attracted sediments causing the mixture to form into mud balls. When the ocean receded, the mud balls dried out causing the interior sections to crack and shrink. Over time, mineral-rich solutions infiltrated the cracks causing crystals to form and fill in the cracks. Septarian nodules, sometimes called lightning stones, can also found on the Lake Michigan shoreline as well as in New Zealand, England, Morocco, and Madagascar.

Septarians are composed of calcite (the yellow centers), aragonite (the brown lines), and limestone (the outer grey surface).  Occasionally, fossils can be seen within or on the surface of the nodules.

CITES

• https://en.wikipedia.org/wiki/Concretion
• Tony Hisgett, https://commons.wikimedia.org/wiki/File:Calcite_septarian_nodule_ROM.jpg
• Sven Teschke, https://commons.wikimedia.org/wiki/File:Septarie_by_Steschke.JPG
• Keith Pomakis, https://commons.wikimedia.org/wiki/File:Septarian_Nodule.jpg
• http://www.therockshed.com/information.html