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 Agate Agate is a beautiful natural chalcedony stone, classified as a semi precious gem and has been used by people as early as the ancient Egyptians in and before 3000 BC! Agate is hard and tough enough to be incorporated into jewelry and other ornamental items. Color: Blue, green, yellow,orange, brown, gray Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.530 - 1.539 Hardness: 6.5 - 7 Density: 2.57 - 2.64 Occurrence: Scotland, U.S.A., India, England, Italy, Brazil, Uruguay, Germany, Egypt, Indonesia, and many other localities.
| 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 Amethyst As a member of the quartz family, amethyst is one of the most common, hence under-appreciated, gemstones on the market. Color: purple, violet Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.544 - 1.553 Hardness: 7 Density: 2.66 Occurrence: Brazil, Uraguay, Bolivia, Madagascar, Russia, USA, Zambia
| Natural Ametrine Ametrine is a unique semi-precious gemstone that is a blend of citrine and amethyst.It has a warm, soft cream color that shows hints of both its lilac and honey hued parents. Color: purple, violet, yellow Categories: semi-precious stone Chemical Composition: SiO2 Crystal Group: Hexagonal Refractive Index: 1.544 - 1.553 Hardness: 7 Density: 2.66 Occurrence: Brazil, Bolivia
| Natural Andalusite Andalusite is popular as a collector stone but is seldom used in jewelry probably because of it's unavailability. With a hardness of 7 - 7.5 andalusite is tough enough to be used in jewelry. Andalusite, especially in the rough, can easily be confused with alexandrite because of similarities in color Categories: semi-precious stone Chemical Composition: Al2SiO5 Crystal Group: Orthorhombic Refractive Index: 1.628 - 1.647 Hardness: 7 - 7.5 Density: 3.13 - 3.21 Occurrence: Brazil, Sri Lanka, Spain, East Africa, Burma, U.S.A.
| Natural Andradite Andradite is a Garnet, belonging to the Garnet group. It has the most powerful luster of any garnet, and this makes it a reputable gem. Color: brown, greenish brown, yellowish green, green Categories: semi-precious stone Chemical Composition: Ca3Fe2(SiO4)3 Crystal Group: Cubic Refractive Index: 3.82 ¨C 3.85 Hardness: 6.5 Density: 1.888 ¨C 1.889 Occurrence: Mexico, Korea, Namibia, Russia, Iran, South Africa
| Natural Apatite Apatite displays strong fluorescence under short wave ultra-violet light. There is a particularly intense and deeply saturated, geenish-blue (aka swiss blue) variety from Madagascar known as "Neon Apatite" that is becoming quite popular in the gem trade. Color: yellow, green, below, violet Categories: semi-precious stone Chemical Composition: Phosphate group Crystal Group: Hexagonal Refractive Index: 1.63-1.64 Hardness: 5 Density: 3.17-3.23 Occurrence: Burma, Ceylon, Madagascar, Mexico, Canada, India
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