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-resinous luster, and amorphous crystal structure with no cleavage. Exhibits a dark body tone with vibrant play-of-color.
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Physical properties
Hardness of 5.5-6.5 on the Mohs scale, vitreous to sub-resinous luster, and amorphous crystal structure with no cleavage. Exhibits a dark body tone with vibrant play-of-color.
Formation & geological history
Formed from silica-rich groundwater solutions depositing in sedimentary rock voids over millions of years.
Uses & applications
Prized globally as a high-end gemstone used in luxury jewelry and collector displays.
Geological facts
Black opals are the rarest and most valuable variety of opal, predominantly mined in Lightning Ridge, Australia.
Field identification & locations
Identify by its dark background color displaying intense spectral flashes of red, green, and blue. Found primarily in New South Wales, Australia.
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