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, vitreous luster, 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, vitreous luster, trigonal crystal system.
Formation & geological history
Forms in metamorphic and igneous rocks, particularly in aluminum-rich and silicon-poor environments like marble and alkali basalts.
Uses & applications
Extensively used in high-end jewelry, watch bearings, and scientific instrumentation due to extreme hardness.
Geological facts
Sapphire is the September birthstone and the variety corundum shares its mineral family with rubies.
Field identification & locations
Identified by its extreme hardness, dichroism, and distinct hexagonal crystal habit when rough; found in Sri Lanka, Madagascar, and Myanmar.
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