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Mexican Fire Opals

Opal is a noncrystalline hydrated form of silica, forming when silica slowly settles out of a dilute water solution. Fire opals are transparent to semi-transparent, resembling gelatin, with red, orange, or yellow body color, with or without play-of-color. The body color is caused by inclusions of iron oxides. They are also sometimes called Mexican opals because most of the best fire opals are found in Mexico.

Image Number: 95-40493
Catalog Number: see acquisition info
Weight: 11.24-143.17 carats
G3968; G2028; G1072; G3886; G2111; G2240; G3964; L. T. Chamberlain, W. A. Roebling, F. A. Lewis


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Smithsonian National Museum of Natural History Department of Mineral Sciences website Credits