Tanzanite

Tanzanite bracelet

Description

A pale-color transparent mineral that has been used as a gemstone. Tanzanite is a variety of zoisite composed of calcium aluminum silicate. Blue gem-quality stones were discovered in Tanzania in 1967. Tanzanite may be colorless, yellow-green, brown or bluish purple and refract flashes of blue, magenta and yellow. Most crystals are greenish gray and contain traces of vanadium. These stones are commonly heat treated (600-700C) to produce a strong sapphire blue color gem.

Tanzanite stone

Synonyms and Related Terms

zoisite; Tansanit (Deut.); tanzanita (Esp.); tanzanite (Fr.)

Other Properties

Pleochroic. Fracture = uneven. Streak = white

Mohs Hardness	6.0 - 6.5
Density	3.2-3.4

Additional Information

Mineralogy Database: Zoisite

Comparisons

Properties of Common Gemstones

Sources Checked for Data in Record

• R.F.Symmes, T.T.Harding, Paul Taylor, Rocks, Fossils and Gems, DK Publishing, Inc., New York City, 1997

• Encyclopedia Britannica, http://www.britannica.com Comment: "tanzanite" Encyclopædia Britannica Premium Service. [Accessed 28 Sept. 2005].

• C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979

• Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Tanzanite (Accessed Sept. 28, 2005)

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998