gemstone
Black Opal
Hydrated amorphous silica (SiO2·nH2O)
AI-generated identification · may be incorrectHardness of 5.5-6.5 on the Mohs scale, vitreous to sub-vitreous luster, and displays a dark body tone with vivid play-of-color.
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Physical properties
Hardness of 5.5-6.5 on the Mohs scale, vitreous to sub-vitreous luster, and displays a dark body tone with vivid play-of-color.
Formation & geological history
Formed from silica-rich groundwater depositing in cracks within sedimentary rock over millions of years.
Uses & applications
Extensively used in high-end jewelry and prized by mineral collectors for its unique optical properties.
Geological facts
Black opals are the rarest and most valuable variety of opal, with dark body tones that make the internal spectral colors intensely vibrant.
Field identification & locations
Identified primarily by its dark matrix and intense play-of-color, found predominantly in Lightning Ridge, New South Wales, Australia.
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