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 ¨C 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.
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