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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…
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Uses of Magnesite
Magnesite has a chemical composition of MgCO3, and when it is heated it will dissociate into MgO and CO2. MgO has an extremely high melting temperature, and that makes it a good refractory material in many steelmaking, metallurgical, and ceramic processes. MgO is one of the most commonly used materials for making the bricks used…
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Properties of Magnesite
Magnesite can be difficult to identify in hand specimens because it often departs from its anticipated properties. It is often cryptocrystalline, which can obscure its cleavage. Magnesite is often silicified or in an admixture with chert, which makes it deceptively hard. The presence of significant chert will also reduce the apparent effervescence with HCl. If…
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How Does Magnesite Form?
Magnesite can form by several processes. Some of the more common are described below.
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What Is Magnesite?
Magnesite is a magnesium carbonate mineral with a chemical composition of MgCO3. It is named after the presence of magnesium in its composition. Magnesite usually forms during the alteration of magnesium-rich rocks or carbonate rocks by metamorphism or chemical weathering. Magnesite is used to produce magnesium oxide (MgO), which serves as a refractory material for the steel industry…