mineral
Corundum
Aluminium oxide (Al2O3)
AI-generated identification · may be incorrectHardness of 9 on the Mohs scale, hexagonal crystal system, pearly to adamantine luster, and pink to reddish-brown color.
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Physical properties
Hardness of 9 on the Mohs scale, hexagonal crystal system, pearly to adamantine luster, and pink to reddish-brown color.
Formation & geological history
Forms in metamorphic and igneous rocks, typically in aluminum-rich, silica-deficient environments like marble and syenites.
Uses & applications
Used as an abrasive, in precision instrument bearings, and as gemstones (ruby and sapphire).
Geological facts
Corundum is the second-hardest natural mineral on Earth, surpassed only by diamond.
Field identification & locations
Identified by its extreme hardness, heavy weight, and distinct barrel-shaped hexagonal crystal habit; found worldwide.
