Gemstone Chart |
Natural Brazilianite Brazilianite is a wonderful gemstone that is rare and hard to find. The main production area is in the Minas Gerais region of Brazil. Color: yellow, greenish yellow Categories: semi-precious stone Chemical Composition: A hydrous sodium aluminum phosph Crystal Group: Monoclinic Refractive Index: 1.603 - 1.623 Hardness: 5.5 Density: 2.940 - 2.998 Occurrence: Minas Gerais, Brazil; New Hampshire, U.S.A.
| 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 Chrome Tourmaline Chrome tourmaline is a beautiful bottle-green variety of the gemstone. Gem-quality chrome tourmaline is quite pricey and is found in East Africa. Color: dark green, light green, yellowish green Categories: semi-precious stone Chemical Composition: (NaCa)(LI,MgFe,Al)9B3Si6(O,OH)31 Crystal Group: Hexagonal Refractive Index: 1.624(+.005, -.005) - 1.644(+.006, -.006) Hardness: 7-7.5 Density: 3.06 (.05, +.15) Occurrence: East Africa
| 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 Chrysocolla Quartz Chrysocolla quartz is chalcedony mixed with varying amounts of chrysocolla. The chrysocolla provides the robin's egg blue coloration, and the quartz provides sufficient hardness for use in jewelry. Color: green, blue, white Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.544 - 1.553 Hardness: 7 Density: 2.66 Occurrence: Arizona, Mexico
| Natural Color Change Garnet Color Change Garnet is one of the most rare, interesting, and phenomenal of all gems.Color Change Garnet gem stone rough from Madagascar Gems is fine quality. Color: Color changing from green or lavender to red. Categories: semi-precious stone Crystal Group: Cubic Refractive Index: Nesosilicate Hardness: 7-7.5 Density: 3.8 Occurrence: East Africa, Madagascar, Sri Lanka
| Natural Color Change Sapphire A rare variety of sapphire, known as color changing sapphire, exhibits different colors in different light. A color change sapphire is blue in natural light, and violet in artificial light. A similar effect is also seen in alexandrite. Color: Color changing blue to purple, greenish brown to red Categories: semi-precious stone Chemical Composition: AL22O3 Crystal Group: Hexagonal Refractive Index: 1.759-1.778 Hardness: 9 Density: 4 Occurrence: Ceylon, East Africa
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