Gemstone Chart |
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 Tanzanite Tanzanite is a rare gem which has been celebrated as one of the most exciting finds of the 20th century. Manuel D’Souza discovered the gem in 1967 in Tanzania. Because tanzanite is relatively soft, it is not usually set in necklaces and earrings, so the tiara is truly a rarity. Color: Blue, Blue Purple, Green, Pink. Categories: semi-precious stone Chemical Composition: Ca2(Al,OH)Al2(SIO4) Crystal Group: Orthorhombic Refractive Index: 1.688 - 1.707 Hardness: 6-7 Density: 3.30 (+.10, -.10) Occurrence: Tanzania
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