Sphene - An Extraordinary Bright Gem
SPHENE - A Dichroic Gem
Sphene is a beautiful yellow green to green gemstone which has a very high dispersion.
Sphene
Sphene is an exquisite lemon-yellow or green gemstone, whose name is derived from the Greek root word, 'sphen' as it is generally wedge-shaped. It can also be white or brown or occasionally pink .
Sphene (Titanite)
Chemical composition -- Calcium titanium silicate.
Color -- Yellow, green, brown, red, black.
Sphene
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Sphen, means wedge shaped as it occurs normally, is a brilliant transparent yellowish-green or green with a high lustre and pronounced fire.
SPHENE
Overview: Its name comes from the word "sphen" meaning "wedge shaped", as it normally occurs in wedge shaped crystals. Sphene is also alternatively called Titanite due to its titanium content.
Sphene used in Jewelry
Source: Austria, Brazil, Canada, China, Germany, Italy, Madagascar, Norway, Pakistan, Russia, Sri Lanka, Switzerland, USA ...
Sphene’s magnificent fire, unique color shades, strong pleochroism, adamantine (diamond-like) luster and double refraction (birefringence) make it ideal for earrings and pendants that catch the light, ...
Enhancements
Sphene is not known to be enhanced.
More information on gemstone enhancements.
Sphene ...
Sphene. Northern Areas, Pakistan, 3.4 cm high. (Photo: Jeffrey Scovil; Gem: Bill Larson Collection) ...
Sphene
Stalactitic
Forming as stalactites or stalagmites; cylindrical or cone-shaped ...
Sphene (sometimes called titanite) is a mineral that comes in green, yellow, white, brown or black wedge-shaped crystals (sphene means wedge in Greek). Sphene is used only rarely as a gem (due to its relative softness).
The Sphene name comes from the Greek "sphen", meaning "wedge", from its sharp wedge shaped crystals. The titanite comes from the titanium constituent of it composition. Soluble in sulfuric acid.
Photos
& Locals: ...
in UV Sphene
Crystallography: monoclinic
Colors: yellow, green, brown
Hardness: 5.5
Specific gravity: 3.53
Refractive index: avg. 1.96 v. .12
Pleochroism: strong
Comments: rare, large DR. dispersion higher than diamond.
Inclusions of rutile, calcite, apatite, olivine, sphene, spinel.
Renowned for "pigeon blood color", also for uneven "roiling" of color.
Give off a strong red fluorescence in short and long u.v. light.
Sphene (a gem rarely seen in the trade) and the demantoid garnet (a green gem often called "olivine" in the trade) both have very high dispersive powers exceeding the diamond in this respect.
The sphene structure involves SiO4 tetrahedra with CaO7 and TiO6 polyhedra. Zirconium is the connecting element in zircon [ZrSiO4].
Lapis Lazuli or Lapis - Lapis may contain other minerals, such as calcite, pyrite, amphibole, apatite, diopside, feldspar, sphene, and zircon. The name comes from Arabic "allazward" meaning sky or blue.
Titanite"Collectible brown crystalline mineral once known as sphene.
Topaz"Hardness and good crystals make it a popular mineral.
Turquoise"The most precious phosphate mineral.
brazilianite, kunzite, moonstone, jade (nephrite, jadeite), malachite, sphene
Triclinic systems
3 crystallographic axes of different lengths, all at different angles
none ...
[The doubled facet reflections seen under magnification in this sphene and zircon, serve as clues to gem identity: few species have birefringence this high] ...
Adamantine Refers to the diamond-like luster of a gemstone. Gemstones with a diamond-like luster include diamond (of course), demantoid garnet and sphene.
The stones commonly contain silk-short, fine rutile needle inclusions. Mineral inclusions are also observed such as corundum, calcite, dolomite, spinel, zircon, garnet, apatite, graphite, pargasite and yellowish sphene crystals.
32: Sphene
Sec. IV, Ch. 33: Spodumene
Sec. IV, Ch. 34: Topaz
Sec. IV, Ch. 35: Tourmaline
Sec. IV, Ch. 36: Zircon or Jargoon
Appendix A: Discrimination of Precious Stones
Appendix B
Index ...
 See also: Stone, Color, Diamond, Garnet, Gemstone
  
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