gemstone
Blue Sapphire
Corundum (Al2O3)
AI-generated identification · may be incorrectHardness of 9 on the Mohs scale, blue color caused by iron and titanium impurities, vitreous to adamantine luster, trigonal crystal system, and no cleavage.
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Physical properties
Hardness of 9 on the Mohs scale, blue color caused by iron and titanium impurities, vitreous to adamantine luster, trigonal crystal system, and no cleavage.
Formation & geological history
Forms in aluminum-rich metamorphic or igneous rocks like pegmatites and marbles through high-temperature crystallization over millions of years.
Uses & applications
Extensively used in high-end jewelry, precision instrument bearings, and scratch-resistant watch crystals.
Geological facts
Sapphire is the gem-variety of corundum and shares its mineral family with ruby, which is red due to chromium.
Field identification & locations
Identified by its extreme hardness, high specific gravity, and distinctive hexagonal crystal habit when raw; commonly found in alluvial gravel deposits worldwide.
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