mineral

White Sapphire

Corundum (Al2O3)

Hardness: 9 on Mohs scale; Color: Colorless/Transparent; Luster: Adamantine to vitreous; Crystal system: Trigonal; Cleavage: None (has parting); Specific Gravity: 3.95-4.10

Hardness: 9 on Mohs scale
Color: Colorless/Transparent
Luster: Adamantine to vitreous

Identified March 11, 2026More mineral →

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Physical properties

Hardness: 9 on Mohs scale; Color: Colorless/Transparent; Luster: Adamantine to vitreous; Crystal system: Trigonal; Cleavage: None (has parting); Specific Gravity: 3.95-4.10

Formation & geological history

Formed in aluminum-rich metamorphic rocks (schist, gneiss) and igneous rocks (syenites, pegmatites) under high pressure and temperature. Primary sources are alluvial deposits (river beds) or pipe deposits.

Uses & applications

Used primarily in fine jewelry as a diamond alternative, industrial abrasives, watch crystals, and high-durability optical windows.

Geological facts

Sapphire is the same mineral as Ruby; the only difference is the trace element that provides color. White sapphire is the purest form of corundum, lacking the chemical impurities that create blue or red hues.

Field identification & locations

Identify in the field by its extreme hardness (will scratch glass and topaz easily) and heavy weight for its size. Major locations include Sri Lanka, Madagascar, and Myanmar. Professional gemological testing is needed to distinguish it from White Zircon or Synthetic Moissanite.