Gemstone Chart |
Natural Sapphire Sapphire is a gemstone variety of the mineral corundum,Blue is the main colour of the sapphire. Its beauty, its magnificent colours, its transparency, but also its constancy and durability are qualities associated with this gemstone by gemstone lovers and specialists alike.Fancy sapphires are pure individualism and are just made for lovers of individualistic coloured stone jewellery. They are currently available in a positively enchanting variety of designs - as ring stones, necklace pendants or ear jewellery. Color: blue, bluish purple, bluish violet, greenish yellow, orangy yellow, purple, red, reddish orange, red-orange or orange-red, reddish purple, red-purple or purple-red, slightly purplish red, violet, violetish blue, yellow, yellowish orange, pink Categories: precious stone Chemical Composition: AL22O3 Crystal Group: Hexagonal Refractive Index: 1.759-1.778 Hardness: 9 Density: 4 Occurrence: Sri Lanka, Burma, India, Kenya, Tanzania, Madagascar, Thailand, U.S.A., China
| Natural Sapphirine Sapphirine is a rare mineral, a silicate of magnesium and aluminium.Though Sapphirine clearly falls into the "rare stone" category, it is a relatively durable stone with a Moh's hardness of 7.5. Sapphirine's very distinctive appearance along with their somewhat unusual durability have made them fairly popular with collectors. Color: Pale blue, bluish gray, greenish gray, green, purplish pink Categories: semi-precious stone Crystal Group: Monoclinic Refractive Index: 1.714-1.723 Hardness: 7.5 Density: 3.4-3.5 Occurrence: U.S.A., U.K., Sweden, Czechoslovakia, Japan, South Africa, Greenland, Madagascar, Italy, Sri Lanka
| Natural Sillimanite Sillimanite is an alumino-silicate mineral with the chemical formula Al2SiO5. Sillimanite is a very rare trimorph and it has a common variety called fibrolite. Color: violet blue, grey green, colorless, brown, green, Categories: semi-precious stone Chemical Composition: Al2OSiO4 Crystal Group: Orthorhombic Refractive Index: 1.658 - 1.678 Hardness: 6 - 7.5 Density: 3.25 Occurrence: France, Madagascar, U.S.A., Sri Lanka, Burma. Kenya
| 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 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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