| Share


tanzanite (tănzănˈĪt) [key], beautiful gemstone discovered in 1967 in the Umba Valley near the Usambara Mts. in Tanzania, a precious variety of the mineral zoisite, a calcium aluminum silicate. Zoisite is a common rock-forming mineral and is usually white to gray in color. Tanzanite occurs as orthorhombic crystals, which may be colorless, yellow-green, brown, or blue to violet when found; when these crystals are heated to 300–400°C, many of them turn sapphire blue, which is the preferred color for gemstones. The blue color is attributed to the presence of small amounts of vanadium.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on tanzanite from Infoplease:

See more Encyclopedia articles on: Mineralogy and Crystallography

Premium Partner Content
HighBeam Research
Documents Images and Maps Reference
(from Newspapers, Magazines, Journals, Newswires, Transcripts and Books)

Research our extensive archive of more than 80 million articles from 6,500 publications.

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.

24 X 7

Private Tutor

Click Here for Details
24 x 7 Tutor Availability
Unlimited Online Tutoring
1-on-1 Tutoring