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Opal (variety: Black)

The Roebling Opal is an extraordinary piece of opal rough from Virgin Valley, Nevada. The opal was deposited from silica-rich water in voids that remained after buried tree limbs had rotted away, in some cases resulting in opal casts of the original tree parts. Although extremely beautiful, opal from this locality is not commonly used in jewelry because it tends to craize, or crack.

Image Number: 95-40486
Catalog Number: R22
Weight: 2,585 carats
Gift of John A. Roebling , 1926
Locality: Virgin Valley , Nevada


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