gemstone
Sapphire
Corundum (Al2O3)
AI-generated identification · may be incorrectHardness of 9 on the Mohs scale, typically blue, vitreous luster, trigonal crystal system, and lack of cleavage with conchoidal fracture.
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Physical properties
Hardness of 9 on the Mohs scale, typically blue, vitreous luster, trigonal crystal system, and lack of cleavage with conchoidal fracture.
Formation & geological history
Forms in aluminum-rich metamorphic or igneous rocks like pegmatites and marbles under high pressure and temperature.
Uses & applications
Extensively used in fine jewelry, watch bearings, and scratch-resistant scientific windows.
Geological facts
Sapphire is the precious gemstone variety of corundum, with non-blue variants known as fancy sapphires and red varieties called rubies.
Field identification & locations
Identified by its exceptional hardness, high density, and characteristic barrel-shaped crystal habit; found globally in regions like Myanmar, Sri Lanka, and Madagascar.
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