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Uses of Rhodonite
Rhodonite was once used as ore of manganese in India. Today its only uses are as lapidary materials and as mineral specimens. High-quality crystals of rhodonite can sell for very high prices. Good massive pink- to red-colored material is used as an ornamental stone or gem rough. It is typically used to make cabochons, beads, small sculptures, tumbled stones,…
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Physical Properties
Rhodonite’s diagnostic properties are its pink to red color, hardness, high specific gravity, perfect cleavage, and its close association with black manganese oxides. It is sometimes confused with rhodochrosite, which is softer and effervescent in hydrochloric acid, or thulite, which is usually not associated with black manganese oxides. The physical properties of rhodonite are summarized in the table on…
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Geologic Occurrence
Rhodonite is usually found in metamorphic rocks associated with other manganese minerals. It is also found in rocks that have been altered by contact metamorphism, hydrothermal and metasomatic processes. It is usually massive to granular in occurrence. Rarely, it is found as red triclinic crystals. Rhodonite is an uncommon mineral. It is found in a few small deposits across…
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What is Rhodonite?
Rhodonite is a pink manganese silicate mineral of variable composition that often contains significant amounts of iron, magnesium, and calcium. It has a generalized chemical composition of (Mn,Fe,Mg,Ca)SiO3. Rhodonite is often associated with black manganese oxides which may occur as dendrites, fracture-fillings, or matrix within the specimen. Other names for rhodonite include “manganese spar” and “manganolite.”
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Variscite vs. Turquoise
Variscite and turquoise are sometimes found within the same geographic area, and they also can have a similar appearance in the rough or when cut into cabochons. As a result there has been some confusion, with variscite sometimes being identified as the more common and familiar turquoise. Vendors with uncertainty have been known to use…
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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…