| Gemstone Chart |
 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
|  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 Tsavorite
Tsavorite is the name given to the rich green variety of grossular garnet. Its home is the East-African bushland along the border between Kenya and Tanzania. The shining green tsavorite is a young gemstone discovered in 1967 with a very long geological history.
Color: Green
Categories: semi-precious stone
Chemical Composition: Ca3Al2(SiO4)3
Crystal Group: Cubic
Refractive Index: 1.735 (+.015, -.035)
Hardness: 7
Density: 3.61(-.27, +.12)
Occurrence: Kenya, Tanzania, Madagascar
|  Natural Turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium.The gem turquoise owes it's beauty almost entirely to its superb color. It has been used for ornamentation since 3000BC and possibly before.
Color: Blue, Greenish Blue
Categories: semi-precious stone
Chemical Composition: CuAl6(PO4)4(OH)85H2O
Crystal Group: Triclinic
Refractive Index: 1.62
Hardness: 5.5-6
Density: 2.60- 2.90
Occurrence: Iran, USA, India, Tibet, China, Egypt, Chile, Russia, Australia
|  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.
|
|
|Register|Sign in|Customization
+'/&media=https://www.etoolsage.com/../images/eTools.gif'+'&description='+encodeURIComponent(document.title),'_blank','toolbar=yes, location=yes, directories=no, status=no, menubar=yes, scrollbars=yes, resizable=no, copyhistory=yes, width=600, height=450,top=100,left=350');void(0) "Pinterest")
