Gemstone Chart |
Natural Topaz Topaz is a silicate mineral most often found in igneous rocks of felsic composition. It is a common gemstone that has been used for centuries in jewelry. Gem quality topaz most commonly occurs in nature as a colorless crystal. It is a very popular gemstone. Color: colorless, blue, yellow-brown, pinkish orange, red-orange, red-brown, tan. Categories: semi-precious stone Chemical Composition: AL(F,OH)2SIO4 Crystal Group: Orthorhombic Refractive Index: 1.629 - 1.637 Hardness: 8 Density: 3.52 - 3.56 Occurrence: Brazil, Sri Lanka, Nigeria, Germany, Australia, Japan, Russia, Ireland, Zimbabwe.
| Natural Tourmaline Tourmaline is actually a group of several different minerals which have similar crystal structures, but complex and variable chemical formulas. Tourmaline is the most varicolored of all gemstones. It occurs in all colors, but red, green, and multicolored are its most famous gem colors. Color: blue, bluish green, green, greenish blue, green-blue or blue-green, greenish yellow, orangy red, red, red-orange or orange-red, red-purple or purple-red, slightly purplish red, slightly yellowish green, strongly purplish red, strongly yellowish green, very slightly bluish green, yellowish green, yellow-green or green-yellow, colorless, brown, 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: Brazil, East Africa, Nigeria, Madagascar, U.S.A.
| Natural Triplite Triplite is a rare fluoro-hydroxide phosphate mineral that forms in phosphate rich granitic pegmatites and high temperature hydrothermal veins. The name is from the Greek triplos for triple, in reference to the three cleavage directions. It is a very gemstones and few cut stones have been ever reported. Color: brightly coloured (brown, salmon, flesh-red) Categories: semi-precious stone Chemical Composition: (Mn,Fe2+)2(PO4)(F,OH) Crystal Group: Monoclinic Refractive Index: 1.650 - 1.680 Hardness: 5 - 5.5 Density: 3.44 - 3.90 Occurrence: the Shigar Valley, Pakistan; China; France, Bavaria, Germany; Kimito, Finland; Karibib, Namibia; Maine, and Connecticut, Arizona and Colorado in the United States.
| Natural Zircon Zircon is a mineral belonging to the group of nesosilicates. It is one of the heaviest gemstones, which means that it will look smaller than other varieties of the same weight. Zircon occurs in a wide range of colours,the most popular colour is blue zircon. The wide variety of colours of zircon, its rarity, and its relatively low cost make it a popular collector's stone. Color: Brown, blue, red, orange, white, green Categories: semi-precious stone Chemical Composition: ZrSiO4 Crystal Group: Tetragonal Refractive Index: 1.780-1.984 Hardness: 7.5 Density: 4.00-4.73 Occurrence: Ceylon, Burma,France, Norway, East Africa,Australia, SE Asia.
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