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Al2SiO5 A blue or light-green neosilicate mineral; crystallizes in the triclinic system, and luster is vitreous to pearly; occurs in long, thin bladed crystals and crystalline aggregates. Also known as cyanite; disthene; sappare.



(also called disthene), a silicate mineral with the chemical composition Al2[SiO4]O. Kyanite contains up to 63.1 percent Al2O3 and sometimes up to 2 percent admixtures of iron oxide or chromium oxide. It crystallizes in the triclinic system, forming long columnar or tabular crystals and their aggregates. Its color ranges from greenish blue to dark blue-green and yellow; sometimes it is colorless. The mineral is characterized by a sharp anisotrophy in hardness. In the direction parallel to the length of the crystal the hardness equals 4.5, and in the direction at right angles, it is up to 7.5. The density ranges from 3,560 to 3,680 kg/m3. Kyanite is formed with the plutonic metamorphism of clay-rich sedimentary rocks; it is also encountered in quartz veins and contact zones of pegmatites. It is used as a valuable high-alumina raw material for refractory and acidresistant articles and for spark plug insulators for internal combustion engines.

References in periodicals archive ?
Like the Kyanite Captains' debut album "Wake Up Call," the follow-up CD is being recorded at Silk City Music Factory in Manchester, CT under producer and co-owner Phil Mann.
andulusite, kyanite, sillimanite); ones often sold in rock and mineral stores (agatized dinosaur bone and coprolites); and "common" opals that are anything but, as color photos of loose and mounted gems show.
Deposits of dolomite, limestone, graphite, quartzite, kyanite, mica, iron and copper are also found in large number.
Moreover, the metahyaloclastitic matrix of some submarine breccias contains paragonite, garnet and kyanite, and fragments in the breccia itself may contain almandine garnet growing around ilmenite aggregates.
From left: Jellyfish necklace by MISIS, $490; matte kyanite petal necklace with 18k gold daffodil motif, tourmilated quartz and rock crystal beads by Joan Hornig Jewelry, $2,400 (available at Bergdorf Goodman, NYC); cuff bracelet 18k and 24k gold with a black diamond by Darcy Miro, $10,600.
Ancient Armor inspires a hip new glamour at Terra Nova with an icy cool and ethereal combination of silver, blue kyanite and pearls ($325).
18k white gold kyanite ring channel set with tapered baguettes ($3,700), Gary Ptak.
I'd use a lot of the same stones that people use when meditating," she says, "like kyanite and chrysoprase.
Other minerals known to exist in Botswana include agates, fluorite, kyanite, silver, antimony, lead, graphite, limestone, talc, gypsum, uranium, chromite, iron, platinum, zinc, feldspar and kaolin.