Gemstone Chart |
Natural Actinolite Actinolite is a natural mineral with the chemical formula Ca2(Mg,Fe)5Si8O22(OH)2.the crystals have a hardness of 5.5 on Moh¡¯s scale, and there are two directions of cleavage. Natural actinolite is semi-precious to precious stone used in jewelry and other adornments. Color: Green, Brown Categories: semi-precious stone Chemical Composition: Amphibole Group Crystal Group: Monoclinic Refractive Index: 1.620 - 1.642 Hardness: 5.5 Density: 3.05 Occurrence: Tanzania
| Natural Alexandrite Alexandrite was discovered in 1830 in the Ural mountains of Russia. Alexandrite is also found in Sri Lanka, Brazil, India, Tanzania, Zimbabwe, and most recently in Madagascar. The alexandrite variety of chrysoberyl is one of the rarest and most sought after of all gems. Color: changing from green to red Categories: semi-precious stone Chemical Composition: BeAl2O4 Crystal Group: Orthorhombic Refractive Index: 1.741 - 1.760 Hardness: 8.50 Density: 3.73 Occurrence: Tanzania, India, Russia, Madagascar, Sri Lanka, Zimbabwe, Zambia
| Natural Axinite Axinite is considered to be a semi-precious gemstone and while limited in nature, gems of good color and size are available, however, faceted stones above 1 carat are rare. Despite being a bit brittle, Axinite¡¯s brilliance and sumptuous colors ranging from a rich clove color to a vivid blue, make it a exquisite and unique gemstone that is keenly sought after by collectors and connoisseurs alike. Currently, the most in demand colors of Axinite are the earth toned browns. Color: Yellow, brown, violet, brownish red Categories: semi-precious stone Crystal Group: Triclinic Refractive Index: 1.673 ¨C 1.693 Hardness: 6.5 - 7 Density: 3.29 Occurrence: Baja CA, USA; Tanzania
| Natural Chalcedony Chalcedony is a catch all term that includes many well known varieties of cryptocrystalline quartz gemstones. They are found in all 50 States, in many colors and color combinations, and in sedimentary, igneous, and metamorphic rocks. Color: grayish, purple, white, green, blue, lavender, yellow, brown Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.530 - 1.539 Hardness: 6.5 Density: 2.57 ¨C 2.64 Occurrence: Brazil, U.S.A. Germany, India, Uruguay, Austarlia, Egypt, Italy, Scotland, South Africa, Namibia, Madagascar, Mexico, Tanzania, and many other localities throughout the world.
| 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 Chrysoberyl Cats Eye Chrysoberyl cats eye is a very rare and expensive gemstone which is found in small quantities in Sri-Lanka and Brazil. The cats eye is present because the stone has chatoyancy in its make up and this effect cause the ¡®eye¡¯ which moves as the gem is gently turned . Color: yellow, greenish yellow, yellowish green 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 Chrysoprase Chrysoprase is a gemstone variety of chalcedony or cryptocrystalline quartz, colored by trace amounts of nickel. Categories: semi-precious stone Chemical Composition: SIO2 Crystal Group: Hexagonal Refractive Index: 1.544 - 1.553 Hardness: 7 Density: 2.65 - 2.66 Occurrence: Australia, Tanzania
| Natural Enstatite Enstatite is a relatively common mineral, but is rarely used for jewelry purposes. It is generally cut for gem connoisseurs and collectors rather than for the common consumer. Color: Gray, green, brown, orange-brown, yellowish-brown, colorless, pale yellow. Categories: semi-precious stone Chemical Composition: MgSiO3 Crystal Group: Orthorhombic Refractive Index: 1.663-1.673 Hardness: 5.5 Density: 3.26-3.28 Occurrence: South Africa, Burma, Tanzania, Sri Lanka, Kenya, Germany, Norway, Greenland
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