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Variscite as a Gemstone
Variscite of exceptional color and appearance is often cut into cabochons and sold as a collector stone. These cabochons are also used in jewelry. If you are interested in variscite jewelry, you will probably have a hard time finding it in a jewelry store. Variscite is a rare material, the jewelry-buying public is not familiar…
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Geologic Occurrence of Variscite
Variscite is rarely found in crystals that are large enough to see without magnification. Instead it usually occurs in cryptocrystalline masses, nodules, veins, or cavity fillings. These usually form as a secondary mineral in near-surface deposits where phosphate-bearing waters interact with minerals that contain aluminum. In the United States, variscite is found in Nevada, Utah, and Wyoming.…
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What is Variscite?
Variscite is a rare hydrated aluminum phosphate mineral with a chemical composition of AlPO4•2H2O. It is usually green in color, ranging from yellowish green to bluish green. It does not have any significant industrial use. Variscite specimens of exceptional color and appearance are often cut into gemstones, used to make small sculptures, or used as an ornamental stone in…
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Lepidolite As a Gem Material
Lepidolite as a mineral lacks the hardness and tenacity to be a good gem material. However, it is sometimes impregnated with quartz, and that gives it durability. Lepidolite impregnated with quartz makes an attractive pink to purple gemstone, but what makes these stones even more desirable are the bright flashes that occur when the mica cleavage surfaces reflect light.…
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Uses of Lepidolite
The most important use of lepidolite has been as a minor ore of lithium metal. This use was more important in the first half of the 1900s than it is today. Today most lithium is produced from brine and evaporite deposits in South America, where lithium can be extracted more economically. Small amounts of rubidium sometimes…
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Composition and Properties
Lepidolite has a chemical composition that ranges in a solid solution series from that of polylithionite KLi2Al(Si4O10)(F,OH)2 to that of trilithionite K(Li1.5Al1.5)(AlSi3O10)(F,OH)2. This compositional range of lithium mica is known as the lepidolite series. The properties of lepidolite make most specimens easy to identify. If you find a pink to purple mica mineral, it is probably…
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Color In Lepidolite
Most specimens of lepidolite have pink, red or purple as their dominant hue. These are the expected colors of lepidolite. The mineral sometimes has a dark tone, which gives it a grayish appearance. Rare specimens of lepidolite are colorless or yellow. Many people assume that lithium produces the color of lepidolite; however, lithium rarely serves…
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Geologic Occurrence of Lepidolite
Lepidolite can only form in geochemical environments where high concentrations of lithium are available for mineral formation. Lepidolite is a rare mineral because these geochemical situations rarely occur. The lithium ion is very small, and it does not readily substitute in other minerals. As a result, it is usually one of the last ions to…
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What Is Lepidolite?
Lepidolite is the name of a rare lithium-rich mica mineral that is usually pink, red, or purple in color. It is the most common lithium-bearing mineral and serves as a minor ore of lithium metal, with rubidium and cesium sometimes being byproducts. When impregnated with quartz, lepidolite is used as a minor gemstone. Flakes of lepidolite are sometimes responsible for the…
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Magnesite Gemstones
Magnesite is commonly used to make tumbled stones, beads, and cabochons. White magnesite is porous. It has the ability to be cut and reliably absorb dye to produce almost any color. Magnesite dyed a turquoise color has been a disclosed and undisclosed substitute for turquoise for nearly 100 years. A lot of people have been fooled by…