gemstone
Blue Sapphire
Corundum (Al2O3)
AI-generated identification · may be incorrectHardness of 9 on the Mohs scale, deep blue color due to iron and titanium impurities, adamantine to vitreous luster, and trigonal crystal system.
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Physical properties
Hardness of 9 on the Mohs scale, deep blue color due to iron and titanium impurities, adamantine to vitreous luster, and trigonal crystal system.
Formation & geological history
Forms in aluminum-rich, silica-deficient metamorphic or igneous rocks like pegmatites and marbles over millions of years.
Uses & applications
Widely used in high-end jewelry, industrial bearings, watch crystals, and scientific instrumentation.
Geological facts
Sapphire is the second hardest natural mineral on Earth, surpassed only by diamond. Famous specimens include the Star of Asia.
Field identification & locations
Identified by its extreme hardness, high specific gravity, and distinctive barrel-shaped hexagonal crystals; commonly found in alluvial gravel deposits in countries like Sri Lanka, Madagascar, and Myanmar.
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