mineral

Yellow Sapphire

Corundum (Al2O3) with iron impurities

Hardness: 9 on Mohs scale; Color: vivid yellow to golden; Luster: Adamantine to vitreous; Crystal system: Trigonal; Cleavage: None; Specific gravity: 3.95-4.03

Hardness: 9 on Mohs scale
Color: vivid yellow to golden
Luster: Adamantine to vitreous

Identified June 1, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 9 on Mohs scale; Color: vivid yellow to golden; Luster: Adamantine to vitreous; Crystal system: Trigonal; Cleavage: None; Specific gravity: 3.95-4.03

Formation & geological history

Formed in metamorphic rocks like marble or gneiss, and igneous rocks like syenite. They are often found in secondary alluvial deposits after weathering from host rocks.

Uses & applications

Primary use is in high-end jewelry as a gemstone. It is also significant in Vedic astrology (Pukhraj). Industrial-grade corundum is used for abrasives and watch crystals.

Geological facts

Yellow sapphire is the second hardest natural gemstone after diamond. Trace amounts of iron are what give this variety of corundum its distinctive yellow hue.

Field identification & locations

Identify by its extreme hardness and high density. It lacks the 'fire' of yellow diamond but has a deep, rich glow. Common sources include Sri Lanka, Madagascar, and Thailand.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic