Zoisite


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Related to Zoisite: epidote

zoisite

[′zȯi‚sīt]
(mineralogy)
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.

Zoisite

 

(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.

References in periodicals archive ?
0 cm in diameter), is compositionally zoned and exhibits an inclusion-rich (quartz, amphibole, zoisite and rutile) core overgrown by an inclusion-poor rim.
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.
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).
That's why you'll find Zababa, Zincenite, Zippeite, Zoisite, Zoubekite, Zunyite, Zussmanite, Zvyagintsevite, Zweiselite in the Z section of the alphabet.
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.
Mohsin said Pakistan is blessed with vast natural reserves of precious, semi precious and colored gemstones, including ruby, sapphire, emerald, tourmaline garnet, topaz, peridot, aquamarine, spinal, pargasite, diopsite, moonstone, serpentine, jade, epidote, pink beryl (morganite), goshnite, sphene, zoisite, turquoise, epitite, agite etc and almost all known varieties of quartz.
8 kbar/522-526oC, in agreement with the appearance of zoisite inclusions in this region.