Gemstone Chart |
Natural Chrysoberyl The Chrysoberyl family is best known for the more valuable alexandrite and catseye varieties. Faceted chrysoberyl is a beautiful gem which is not as well known in its own right. Apart from the high hardness, it takes a good polish and has a good luster. Color: yellow, green, color changing, red, blue-green, greenish-yellow or brown Categories: semi-precious stone Chemical Composition: BeAl2O4 Crystal Group: Orthorhombic Refractive Index: 1.741 - 1.760 Hardness: 8.5 Density: 3.73 Occurrence: Ceylon, Tanzania, Russia, Madagascar, Brazil.
| Natural Hemimorphite Hemimorphite is a usually white or colorless mineral, essentially Zn4Si2O7(OH)2·H2O, an important ore of zinc. Also called calamine. Color: Light blue, dark blue, green ,white. Categories: semi-precious stone Chemical Composition: (Zn4Si2O7(OH)2.H2O) Crystal Group: Orthorhombic Refractive Index: 1.612-1.633 Hardness: 5 Density: 3.44 Occurrence: Franklin and Sterling Hill New Jersey, New Mexico, Montana, Arizona, U.S.A; Congo; Nerchinak in Transbaikalia, Siberia; Zambia; Santa Eulalia and Mapimi, Mexico; England; Wenshan, Yunnan Province, China.
| Natural Iolite Iolite is a popular and interesting gemstone, and is the gem variety of the mineral cordierite.It has also been called water sapphire because it looks very much like a blue sapphire. Color: violet, blue, dark blue, Categories: semi-precious stone Chemical Composition: MG2AL4SI5O18 Crystal Group: Orthorhombic Refractive Index: 1.53 - 1.55 Hardness: 7 - 7.5 Density: 2.57 - 2.66 Occurrence: Sri Lanka; Burma; India; Tsivory,Madagascar; Canada; Namibia; Tanzania; Norway; U.S.A.; Brazil
| Natural Kornerupine Kornerupine is a rare mineral occasionally used as a gemstone. It appears frequently in parcels from Ceylon and may be confused with beryl, peridot, topaz, or quartz. Color: Brown, brownish red, yellow-green, light green, blue green Categories: semi-precious stone Crystal Group: Orthorhombic Refractive Index: 1.665 – 1.683 Hardness: 6.5 Density: 3.25 - 3.35 Occurrence: Ceylon, Tanzania
| Natural Sillimanite Sillimanite is an alumino-silicate mineral with the chemical formula Al2SiO5. Sillimanite is a very rare trimorph and it has a common variety called fibrolite. Color: violet blue, grey green, colorless, brown, green, Categories: semi-precious stone Chemical Composition: Al2OSiO4 Crystal Group: Orthorhombic Refractive Index: 1.658 - 1.678 Hardness: 6 - 7.5 Density: 3.25 Occurrence: France, Madagascar, U.S.A., Sri Lanka, Burma. Kenya
| 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.
|
|