Gemstone Chart |
Natural Topaz Topaz is a silicate mineral most often found in igneous rocks of felsic composition. It is a common gemstone that has been used for centuries in jewelry. Gem quality topaz most commonly occurs in nature as a colorless crystal. It is a very popular gemstone. Color: colorless, blue, yellow-brown, pinkish orange, red-orange, red-brown, tan. Categories: semi-precious stone Chemical Composition: AL(F,OH)2SIO4 Crystal Group: Orthorhombic Refractive Index: 1.629 - 1.637 Hardness: 8 Density: 3.52 - 3.56 Occurrence: Brazil, Sri Lanka, Nigeria, Germany, Australia, Japan, Russia, Ireland, Zimbabwe.
| Natural Tsavorite Tsavorite is the name given to the rich green variety of grossular garnet. Its home is the East-African bushland along the border between Kenya and Tanzania. The shining green tsavorite is a young gemstone discovered in 1967 with a very long geological history. Color: Green Categories: semi-precious stone Chemical Composition: Ca3Al2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.735 (+.015, -.035) Hardness: 7 Density: 3.61(-.27, +.12) Occurrence: Kenya, Tanzania, Madagascar
|
|