Corundum

Corundum var. Ruby

Corundum is a mineral comprised of aluminium oxide. The mineral is known for its distinct formation of hexagonal crystals. Corundum occurs in two gemstone varieties, including Ruby, the distinct red variety, and Sapphire, the variety that includes all other colors of Corundum.

Uses

Corundum has significant use as a gemstone, with red Ruby and blue Sapphire being the most popular varieties. In addition, Corunudum has industrial applications as a relatively plentiful high-hardness material.

Notable Localities

Fine Corundum in the form of Ruby has been found in Mogok, Burma (Myanmar), while Corundum of multiple varieties have been found in Sri Lanka, Vietnam, and Madagascar. Pink Rubies embedded in green Zoistite have been found in the Kilimanjaro Region of Tanzania,

Properties
Chemical FormulaAl2O3
Hardness9-9
Crystal SystemTrigonal
Mineral ClassOxides
LusterAdamantine, Vitreous, Pearly