gemstone
White Opal
Hydrated amorphous silica (SiO2·nH2O)
AI-generated identification · may be incorrectHardness of 5.5 to 6.5 on the Mohs scale, white or light body color with subtle play-of-color, vitreous to sub-vitreous luster, and amorphous crystal structure with no cleavage.
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Physical properties
Hardness of 5.5 to 6.5 on the Mohs scale, white or light body color with subtle play-of-color, vitreous to sub-vitreous luster, and amorphous crystal structure with no cleavage.
Formation & geological history
Formed from a solution of silicon dioxide and water seeping into cracks and voids in sedimentary or volcanic rock strata over millions of years.
Uses & applications
Primarily cut and polished into cabochons for fine jewelry and highly prized by mineral collectors.
Geological facts
Opals contain up to 21% water by weight and display a unique play-of-color caused by the diffraction of light through microscopic silica spheres.
Field identification & locations
Identified by its light body tone and lack of crystalline cleavage; primarily sourced from major deposits in Australia and Ethiopia.
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