Gemstone Chart |
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 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 Bi Color Tourmaline Bi color tourmaline is the name given to tourmaline which displays more than one color in the same cystal.It is classified as a semi-precious stone. Color: Green, red, yellow, orange. Brown, green, pink 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, Brazil, USA, Afghanistan, Nigeria, Madagascar
| 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 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
| Natural Grossularite A member of the garnet group, grossularite is found in a variety of colors including, yellow, brown, white, colorless, green, violet-red, and orangey red. Color: Brown, yellow, green Categories: semi-precious stone Chemical Composition: Ca3Al2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.72-1.748 Hardness: 7.25 Density: 3.65 Occurrence: Canada, East Africa, Pakistan, New Zealand, Ceylon, South Africa, U.S.A.
| Natural Idocrase Primarily a green color that will resemble jade.idocrase is one stone that is sometimes mistaken for jade by jewelers and consumers alike. Idocrase is from the greek and means mixed form, an allusion to its crystals showing a mixture of other mineral forms. Color: normally green, but also can be brown, yellow, blue and/or purple. Categories: semi-precious stone Chemical Composition: nesosilicate or sorosilicate Crystal Group: Tetragonal Refractive Index: 1.71 - 1.73 Hardness: 6.5 Density: 3.3 - 3.5 Occurrence: Quebec, Canada; California and the New England region of USA; Mt Vesuvius, Italy; Ural Mountains, Russia, Switzerland, East Africa
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