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Related to Zoisite: epidote


Ca2 Al3Si3O12(OH) A white, gray, brown, green, or rose-red orthorhombic mineral of the epidote group consisting of a basic calcium aluminum silicate and occurring massive or in prismatic crystals.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(after the Slovenian enlightener S. Zois [1747–1819]), a mineral of the class of nesosilicates, with a chemical composition of Ca2Al3 [SiO4] [Si2O7](OH). The typical impurities are Fe3+, Fe2+, Mn, Mg, and, less frequently, Cr, V3+, Na, and K. The structure of zoisite is based on single and twinned tetrahedrons of [SiO4]4– radicals. Zoisite crystallizes in the orthorhombic system, forming prismatic crystals with striations on the faces. It is usually found in granular, columnar, fibrous, and occasionally radiated aggregates. The color is gray or greenish. Manganese-containing zoisite, called thulite, is pink; the chromium-containing variety is bright green. The vanadium-containing zoisite, called tanzanite, exhibits dichroism between dark blue and red violet. Zoisite has a hardness of 6–6.5 on Mohs’ scale and a density of 3,250–3,370 kg/m3.

Zoisite is a rock-forming mineral for several metamorphosed shales and hydrothermally altered basic igneous rocks (it is the chief component of saussurite). It is also found in crystal-bearing veins, skarns, corundum plagioclasites (anorthosites), and other formations. Certain transparent colored varieties are used in jewelry-making.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
It's a gem-quality zoisite ranging in colour from deep blue to burgundy red through violet and purple and several gem hunters have claimed they were the first to find it.
Wilson and partners are exploring the possibility of extracting a mineral called zoisite from the mountain, which may, or may not, have a bizarre application.
UBAIDULLAH QADRI: Pakistan has enormous wealth of expensive gems such as ruby, emerald, tourmaline, garnet, topaz, peridot, aquamarine, spinel, pargasite, diopside, moonstone, pink topaz, sapphire, zircon, feldspar, agate, serpentine jade, epidote, pink beryl (morganite), purple beryl, sphene, zoisite, lapis lazuli, turquoise, and kunzite etc.
Of course, the blues (and purple-blues, and some yellows) are tanzanite zoisite, and the greens are "tsavorite" grossular and chromium-rich diopside.
The REE in clastic sediments are concentrated in detrital accessory minerals, mainly phosphates (notably monazite and apatite for LREE and xenotime for HREE), minor silicates (notably allanite, titanate, and zoisite for LREE, garnet and zircon for HREE), and adsorbed to clays (especially HREE).
(a) The long vowel sound is preceded and succeeded by a short 's' sound Long A Sevssel (the name of 2 villages on the upper Rhone), sayst Long E deceased, caecitis Long I incisor, syce (an Indian horse groom) Long O saussurite (variety of the mineral zoisite), society Long U disuse
Other minor constituents of marbles can include fluorite, apatite, brucite, laumontite, olivine, scheelite, spinel, zoisite, and magnetite.
Primary ores, assigned to the gold-sulphide formation, are represented by metasomatically altered rocks composed of carbonates, quartz, micas, chlorite and zoisite. The discovery of Olimpiadninskoe is one of the proofs for the high potential of finding further deposits in the Yenisei goldfield.