Difference between revisions of "Andradite"
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A type of [[garnet|garnet]] composed of a calcium iron silicate. The color of andradite may be yellow, red, green, brown or black. Bright green andradite, or demantoid, is also called the emerald of the Urals. Gemstone quality andradite is mined in the Ural Mountains, Italy, Switzerland, Norway, France, and in the United States (Arkansas and New Jersey). | A type of [[garnet|garnet]] composed of a calcium iron silicate. The color of andradite may be yellow, red, green, brown or black. Bright green andradite, or demantoid, is also called the emerald of the Urals. Gemstone quality andradite is mined in the Ural Mountains, Italy, Switzerland, Norway, France, and in the United States (Arkansas and New Jersey). | ||
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== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
garnet; demantoid (green, emerald of the Urals); topazolite (yellow); melanite (brown or black); andradita (Esp.); andradite (Port.); Andradit (Deut.); andradiet (Ned.) | garnet; demantoid (green, emerald of the Urals); topazolite (yellow); melanite (brown or black); andradita (Esp.); andradite (Port.); Andradit (Deut.); andradiet (Ned.) | ||
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== Physical and Chemical Properties == | == Physical and Chemical Properties == | ||
Revision as of 13:16, 26 April 2022
Description
A type of Garnet composed of a calcium iron silicate. The color of andradite may be yellow, red, green, brown or black. Bright green andradite, or demantoid, is also called the emerald of the Urals. Gemstone quality andradite is mined in the Ural Mountains, Italy, Switzerland, Norway, France, and in the United States (Arkansas and New Jersey).
Synonyms and Related Terms
garnet; demantoid (green, emerald of the Urals); topazolite (yellow); melanite (brown or black); andradita (Esp.); andradite (Port.); Andradit (Deut.); andradiet (Ned.)
Physical and Chemical Properties
- Fracture = conchoidal
- Luster = vitreous to resinous.
- Streak = colorless.
- Birefringence = none.
- Dispersion = 0.057
- Pleochroism = none.
- UV fluorescence = inert
| Composition | Ca3Fe2Si3O12 |
|---|---|
| Mohs Hardness | 6.5 - 7.0 |
| Density | 3.9 g/ml |
| Refractive Index | 1.887 |
Comparisons
Resources and Citations
- Mineralogy Database: Andradite
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971
- Encyclopedia Britannica, http://www.britannica.com Comment: andradite [Accessed May 20, 2003].
- C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979