Gemstone Chart |
Natural Spessartite The Spessartite is one of the most popular of all garnets. It is highly desired by collectors, jewelry designers and gem lovers.The sources for gem quality spessartine are Sri Lanka and Brazil. Color: Orange, yellow, brown Categories: semi-precious stone Chemical Composition: Mn3Al2(SiO4)3 Crystal Group: Cubic Refractive Index: 1.79-1.81 Hardness: 7.25 Density: 4.14-4.20 Occurrence: Germany, Ceylon, Burma, Nigeria, Maevatanana-Madagascar, Isoanala-Madagascar, East Africa.
| Natural Sphalerite Sphalerite is one of the very few minerals that has a total of six directions of cleavage, and occurs in many different colors. It is an unusual rare gemstone which is craved for by people as it possesses more brilliance than diamonds. Color: Orange, yellow, brown, green Categories: semi-precious stone Chemical Composition: ZnS Crystal Group: Cubic Refractive Index: 2.37 Hardness: 3.5-4 Density: 4.05 Occurrence: Spain, Mexico
| Natural Sphene Sphene is also known as calcium titanium silicate.It is named from the greek word for wedge, because of its typical wedge shaped crystal habit.Because of it's high dispersion and refractive index, a well cut sphene can display stunning brilliance. Sphene is somewhat soft and as a result is more suitable as a pendant than as a ring stone. Sphene is rarely very clean. Color: Green, yellow. brown Categories: semi-precious stone Chemical Composition: CaTiSiO5 Crystal Group: Monoclinic Refractive Index: (1.885-1.990,)-(1.915-2.050) Hardness: 5.5 Density: 3.52-3.54 Occurrence: Austria, Dheirene-Madagascar, India, USA, Brazil.
| 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 Star Sapphire A star sapphire is a lovely gem that exhibits a six pointed star because of the intersection of six thin intersecting inclusions. When the gem is lit from above, the inclusions become quite visible and the star shape appears.A powdery grey-blue star sapphire is the centerpiece of a ring from the Art Deco period. Color: Blue, green blue, violet, blue, black, brown, pink. Categories: semi-precious stone Chemical Composition: AL2O3 Crystal Group: Hexagonal Refractive Index: 1.759-1.778 Hardness: 9 Density: 4 Occurrence: Sri Lanka, Burma, India, East Africa, Ankarana-Madagascar, Thailand.
| Natural Sunstone Sunstone is a sodium-calcium-aluminum-silicate variety of plagioclase feldspar, which when viewed from certain directions exhibits a brilliant spangled appearance; this has led to its use as a gemstone. Color: Orange-red, brownish-red Categories: semi-precious stone Chemical Composition: NaAlSi3O8 Crystal Group: Triclinic Refractive Index: RI 1.54 ¨C1.55 Hardness: 6 Density: SG 2.62 ¨C 2.65 Occurrence: Near Lake Baikal Russia; East Africa; Hastings, Renfrew, and Haliburton, in Ontario Canada; Tvedestrand, Hitero, Norway; Kangayam, India; Maine, Oregon, New Mexico, California, and North Carolina, USA.
| Natural Taaffeite The chemical formula of mineral Taaffeite is indicated by BeMgAl4O8 or Beryllium Magnesium Aluminum Oxide. Taaffeite actually belongs to the Oxides and Hydroxides mineral class. Taaffeite is one of the beautiful and Rarest gems in the world. Color: Mauve, reddish violet, brownish-purple, pink, red, blue. Categories: semi-precious stone Chemical Composition: Beryllium magnesium aluminate wi Crystal Group: Hexagonal Refractive Index: 1.71-1.72. Hardness: 8 - 8.5 Density: 3.60 - 3.71 Occurrence: Tunduru, Tanzania; Sri Lanka
| Natural Tanzanite Tanzanite is a rare gem which has been celebrated as one of the most exciting finds of the 20th century. Manuel DĄ¯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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