Gemstone Chart |
Natural Scheelite Scheelite is a calcium tungstate mineral with the chemical formula CaWO4.With a hardness of 4.5 to 5 on the Moh's ScaleScheelite is a rather soft stone. Traditionally, it was considered a collector's gem and unsuitable for use in jewelry. Color: Yellowish-white, brownish, orange yellow Categories: semi-precious stone Chemical Composition: CaWO4 Crystal Group: Tetragonal Refractive Index: 1.918 - 1.937 Hardness: 4.5 - 5.0 Density: 5.9 - 6.1 Occurrence: Czechoslovakia; Italy; Switzerland; Finland; Cumberland, Cornwall, England; Santa Cruz, Sonora, Mexico; South Dakota, Conneticut, Colorado, Utah, California, Arizona, USA; New South Wales and Queensland, Australia; Mian Yang, and Ping Wu, Sezhuan, China; Hollinger Mine, Ontario, Canada;
| Natural Spinel Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4.Pure spinel is white, but impurities give it a wide range of colors.Almost all colors are used in jewelry, but the most valuable and popular color is the deep red. Spinel is cut into gems for use as jewelry. The deep-red variety, known as ruby spinel, is the most prized form. Color: orange, pink, black, blue, lavender, mauve, greenish blue, and vivid red Categories: semi-precious stone Chemical Composition: MgAl2O4 Crystal Group: Cubic Refractive Index: 1.718 (-.006,+.044) Hardness: 8 Density: 3.60 (-.03, +.30) Occurrence: Mogok, Burma; Sri Lanka; Amboseli district, Kenya; Jemaa district, Nigeria; Matombo, Umba, and Tunduru Tanzania; Hunza, Pakistan; Pamir range, Tajikstan; Luc Yen, Vietnam; Madagascar; Australia; Sweden; Brazil.
| 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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