Muscovite Pseudo-morph Tourmaline Mineral Specimen
HISTORY, NAME, LOCALITIES: Muscovite has been known since antiquity when it was called “white mica” and used in powdered form to whiten paints. In 1850, it was assigned its name, which stems from the Russian principality of Muscovia (Moscow), where thin sheets called “isinglass” were used as a substitute for glass in windows and ovens. Notable collecting localities are found in Namibia, Russia, Brazil, Pakistan, Malawi, Austria, Madagascar, and the United States (Maine, Vermont, South Dakota, Colorado, New Mexico, California, Virginia).
MINERALOGY, PROPERTIES, OCCURRENCE: Muscovite [basic potassium aluminum silicate, KAl2ALSi3O10(OH)2], pronounced MUSS-coh-vite, crystallizes in the monoclinic system as thin, tough, elastic, sheet-like crystals aligned parallel to its perfect, one directional cleavage. Muscovite is a phyllosilicate mineral with a Mohs hardness of 2.0-2.5, vitreous-to-pearly luster, specific gravity of 2.7-3.0, and tendency to form aggregates of well-developed crystals called “mica books.” Muscovite cleaves easily into thin, semi-transparent, silvery-white sheets. As an abundant rock-forming mineral, muscovite is an essential component of many igneous, metamorphic, and sedimentary rocks and achieves its best crystal development in granite pegmatites.
METAPHYSICAL PROPERTIES; LORE, USES: Metaphysical practitioners believe that muscovite aids problem solving, stimulates quickwittedness, and alleviates anger, stress, and self-doubt. Because of its low coefficients of friction and thermal expansion, inertness, and excellent heat- and electrical-insulating properties, muscovite has many uses in industry and is mined extensively.
COLLECTING INFORMATION: Muscovite is collected for its unusual crystal forms, usually as composite specimens in association with such pegmatite minerals as beryl, quartz, and microcline.
HISTORY, NAME, LOCALITIES: Elbaite, pronounced ELL-buh-ite, has been known since antiquity, but was not recognized as a distinct mineral species until 1913. It is named for its type locality on the island of Elba, Italy. Elbaite is collected in Brazil, Afghanistan, Pakistan, Italy, Madagascar, Namibia, Sri Lanka, and the United States (Maine, California).
MINERALOGY, PROPERTIES, OCCURRENCE: Elbaite [basic sodium aluminum lithium borosilicate, Na(Al1.5,Li1.5)Al6(BO3)3(Si6O18)(OH)4], a member of the tourmaline group, crystallizes in the hexagonal system as short-to-long, striated prisms with hexagonal cross sections and flat terminations. It is transparent to translucent, has a vitreous luster, and is usually pink, reddish-pink, green, or blue-green. It has a substantial Mohs hardness of 7.0-7.5, no cleavage, a refractive index of 1.615-1.651, and a specific gravity of 2.9-3.2. Elbaite occurs primarily in lithium-rich, granite pegmatites.
METAPHYSICAL PROPERTIES, LORE, USES: Modern metaphysical practitioners believe that pink elbaite removes fear and negativity, calms the nerves, provides inspiration, and dispels grief; green elbaite is thought to promote compassion and emotional healing and help to connect with the Earth. Green elbaite is especially valuable in helping herbalists to understand the flow of energy between minerals and plants. Elbaite is a valuable and important gemstone. Transparent crystals with rich, pink, green, or blue-green colors are faceted into costly gems.
COLLECTORS’ INFORMATION: Because of its wide range of colors, excellent crystal development, and sometimes large crystal size, collectors value elbaite as individual crystals and as composite specimens in association with quartz and albite.