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| Zoisite | |
|---|---|
| Image required | |
| General | |
| Category | Mineral |
| Chemical formula | calcium aluminium hydroxy silicate (Ca2(Al.OH)Al2(SiO4)3 |
| Identification | |
| Colour | Gray, yellow, blue, green. |
| Crystal habit | Crystals flattened in an acicular manner, may be fibrously curved |
| Crystal system | Orthorhombic |
| Cleavage | Perfect |
| Fracture | Uneven |
| Mohs Scale hardness | 6.5 |
| Luster | Vitreous |
| Refractive index | 1.69-1.70 Biref:0.007-0.010 (biaxial positive) |
| Pleochroism | Present, dichroism or trichroism depending on colour. |
| StreakIn any mineral, its streak refers to the color of its powder. Many minerals may vary in colour, for example, quartz, but their streak normally remains the same color. For quartz, this would be white. Likewise, minerals that look alike, like chromite and m | White or colorless |
| Specific gravity | 3.10-3.38 |
| FusibilityFusibility is the ease with which a material will melt. Materials such as solder requires a low melting point so that when heat is applied to a joint, the solder will melt before the materials being soldered, i. high fusibility. On the other hand, firebri | ? |
| Solubility | ? |
| Major varieties | |
| tanzaniteTanzanite is the blue/purple variety of the mineral zoisite discovered in the Meralani Hills of northern Tanzania in 1967, near the city of Arusha. It is a popular and valuable gemstone when cut, although its durability is somewhat lacking. Tanzanite is n | Gem-quality zoisite, blue-purple |
| thuliteThulite (sometimes called rosaline is an opaque, massive pink variety of the mineral zoisite. Thulite is often mottled with white calcite and occurs as veins and fracture fillings transecting many types of rock. Its colour is said to be attributed to mang | Pink |
| anyoliteAnyolite is considered a variety of the mineral zoisite. Found in Kenya and Tanzania, anyolite is actually a metamorphic rock composed of intergrown green zoisite, black hornblende, and ruby. It is said to be named after the Maasai word anyoli meaning "gr | Often found intergrown with rubyRuby is a red gemstone, a variety of the mineral corundum in which the color is caused mainly by chromium. Natural rubies are exceptionally rare, though artificial ones can be manufactured which are comparatively inexpensive. Rubies are mined in Africa, A |
| chrome zoisite | Green, uncommon |
Zoisite is a calcium aluminium hydroxy silicate belonging to the epidote group of minerals. Zoisite is named after Austrian scientist Baron Sigmund Zois von Edelstein (Baron von Zois) whom discovered the mineral in the Sau-Alp mountains of Austria in 1805. Zoisite was first known as saualpite after its type locality. Transparent material is fashioned into gemstones whilst translucent to opaque material is usually carved into sculptural works.
Zoisite occurs as prismatic , orthorhombic (2/m 2/m 2/m) crystals or in massive form, being found in metamorphic and pegmatitic rock. Zoisite may be blue to violet, green, brown, pink, yellow, gray, or colourless. It has a vitreous lustre and a conchoidal to ueven fracture. When euhedral, zoisite crystals are striated parallel to the principal axis (c-axis). Also parallel to the principal axis is one direction of perfect cleavage. Zoisite is somewhat higher than 6 in hardness and its specific gravity is between 3.10-3.38, depending on the variety. Zoisite streaks white and is said to be brittle.
Sources of zoisite include: Tanzania (tanzanite), Kenya (anyolite), Norway (thulite), Switzerland, Austria, India, Pakistan, and the USA.