Gemstone Chart |
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 Beryl Beryl is a semi-precious clear gemstone which usually comes in greens, yellows, and occasionally pinks, ands various shades thereof. Color: Green, blue, pink, yellow, red Categories: semi-precious stone Chemical Composition: Be3Al2(SiO3)6 Crystal Group: Hexagonal Refractive Index: 1.577(+-.016), 1.583 (+-.017) Hardness: 7.5 Density: 2.67-2.745 Occurrence: Austria, Columbia, Brazil, Russia, East Africa, Australia, Madagascar, South Africa, Zimbabwe, India, Pakistan, Zambia, Nigeria, U.S.A., Afghanistan
| Natural Diamond Diamond is the ultimate gemstone, having few weaknesses and many strengths. It is well known that Diamond is the hardest substance found in nature. Color: White, yellow, brown, black. Rarely, blue, red, or pink. Categories: precious stone Chemical Composition: C Crystal Group: Cubic Refractive Index: 2.417 Hardness: 10 Density: 3.52 Occurrence: Africa, Russia, Canada, Australia, India
| Natural Emerald Emerald, the green variety of the mineral beryl, is the most famous and favored green gemstone.The majority of the worlds gem quality Emeralds come from the Muzo area of Colombia. Color: Blue, Green Blue Categories: precious stone Chemical Composition: Be3Al2(SiO3)6 Crystal Group: Hexagonal Refractive Index: 1.577(+-.016), 1.583 (+-.017) Hardness: 7.5-8 Density: 2.72 (-.05, +.12) Occurrence: Brazil, Pakistan,Russia, East Africa, India, Madagascar, Columbia
| Natural Moonstone The most common moonstone is of the mineral adularia.It is an opaque stone, a simi-clear white, kind of the color of watered down milk.Moonstone Jewellery uses the gemstone moonstone as its main stone. Color: white, blueish white. Categories: semi-precious stone Chemical Composition: KalSI3O8 Crystal Group: Monoclinic Refractive Index: 1.518 ¨C 1.526 Hardness: 6 ¨C 6.50 Density: 2.55 ¨C 2.57 Occurrence: Sri Lanka, India, Madagascar, Burma, Tanzania, U.S.A.
| Natural Oligoclase Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars. Oligoclase is famous for its two gem varieties: Sunstone and Moonstone. Color: green, orange, red, colorless Categories: semi-precious stone Chemical Composition: [Na,Ca]AlSi3O8 Crystal Group: Triclinic Refractive Index: 1.53 - 1.54 Hardness: 6 - 6.5 Density: 2.62 - 2.65 Occurrence: Tvedestrand and Hitero on the south coast of Norway; near Lake Baikal Russia; Ontario, Canada; Tanzania; Kangayam, southern India; France; and in Maine, New Mexico, New York, North Carolina, Pennsylvania, Virginia and Oregon in the USA.
| Natural Rhodochrosite Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. The pink color of rhodochrosite is caused by the element manganese and it is formed when manganese is dissolved by ground water and combines with a carbonate material and then drips off the ceiling of caves and crevices deep underground.Rhodochrosite often forms pink and white bands. It is often carved into figurines or boxes while the tubular stalactite formations are often sliced for use in jewelry. Fine gem quality crystals are sometimes cut into gemstones for use in high end jewelry, but the more common grade is used extensively in silver and gold jewelry. Color: Rose red, raspberry red, pink, grey, fawn, brown Categories: semi-precious stone Chemical Composition: MnCO3 Crystal Group: Trigonal Refractive Index: 1.600 ¨C 1.820 Hardness: 4 Density: 3.45 ¨C 3.70 Occurrence: Argentina; Colorado, U.S.A.; Romania; Hungary; India; South Africa; Saxony, Chile; Peru; Mexico.
| Natural Rhodolite Rhodolite is a beautiful pink to violetish red garnet which was named after the rhododendron flower. Commercially rhodolite is one of the most important garnets. Rhodolite is quite available in small sizes which are relatively low in price. Very fine large rhodolite garnets are rare and are moderate in price. Color: red, purple-red Categories: semi-precious stone Chemical Composition: Al2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.75 - 1.77 Hardness: 7.25 Density: 3.74 - 3.94 Occurrence: Brazil, East Africa, Ceylon, India, Madagascar, Zimbabwe
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