Gemstone Chart |
Natural Sphene Sphene is also known as calcium titanium silicate.It is named from the greek word for wedge, because of its typical wedge shaped crystal habit.Because of it's high dispersion and refractive index, a well cut sphene can display stunning brilliance. Sphene is somewhat soft and as a result is more suitable as a pendant than as a ring stone. Sphene is rarely very clean. Color: Green, yellow. brown Categories: semi-precious stone Chemical Composition: CaTiSiO5 Crystal Group: Monoclinic Refractive Index: (1.885-1.990,)-(1.915-2.050) Hardness: 5.5 Density: 3.52-3.54 Occurrence: Austria, Dheirene-Madagascar, India, USA, Brazil.
| Natural Tanzanite Tanzanite is a rare gem which has been celebrated as one of the most exciting finds of the 20th century. Manuel D¡¯Souza discovered the gem in 1967 in Tanzania. Because tanzanite is relatively soft, it is not usually set in necklaces and earrings, so the tiara is truly a rarity. Color: Blue, Blue Purple, Green, Pink. Categories: semi-precious stone Chemical Composition: Ca2(Al,OH)Al2(SIO4) Crystal Group: Orthorhombic Refractive Index: 1.688 - 1.707 Hardness: 6-7 Density: 3.30 (+.10, -.10) Occurrence: Tanzania
| 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
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