ANDALUSITE - 2 reference results
Andalusite is an aluminium nesosilicate mineral with the chemical formula Al2SiO5.
The variety chiastolite commonly contains dark inclusions of carbon or clay which form an X or a cross in section.
A clear variety first found in Andalusia, Spain can be cut into an interesting gemstone. Faceted andalusite stones give a play of red, green, and yellow colors that resembles a muted form of iridescence, although the colors are actually the result of unusually strong pleochroism.
Occurrence
Andalusite is a common regional metamorphic mineral which forms under low pressure and moderate to high temperatures. Called Lapis Crucifer in ancient texts. The minerals kyanite and sillimanite are polymorphs of andalusite, each occurring under different temperature-pressure regimes and are therefore rarely found together in the same rock. Because of this the three minerals are a useful tool to help identify the pressure-temperature paths of the host rock in which they are found.It was first reported from Andalucia, Spain in 1789.
Related minerals
See also
References
- Mineral galleries
- Webmineral
- Mindat w/ locations
- http://www.gemstone.org/gem-by-gem/english/andalusite.html
Notes
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Last updated on Friday September 12, 2008 at 05:53:17 PDT (GMT -0700)
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This article is licensed under the GNU Free Documentation License.
Last updated on Friday September 12, 2008 at 05:53:17 PDT (GMT -0700)
View this article at Wikipedia.org - Edit this article at Wikipedia.org - Donate to the Wikimedia Foundation
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