mineral

Blue Sapphire

Corundum (Al2O3)

AI-generated identification · may be incorrect

Hardness: 9 on the Mohs scale; Color: Deep blue (due to iron and titanium); Luster: Vitreous (glassy); Crystal Structure: Trigonal/Hexagonal; Cleavage: None (has parting); Specific Gravity: 3.98 - 4.06

Hardness: 9 on the Mohs scale
Color: Deep blue (due to iron and titanium)
Luster: Vitreous (glassy)

Identified January 22, 2026More mineral →

Explore Blue Sapphire in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed in aluminum-rich metamorphic rocks (gneiss/schist) or igneous rocks (alkaline basalts or syenites) through high pressure and temperature. Commonly found in secondary alluvial deposits (river beds).

Uses & applications

Primary use is in high-end jewelry as a precious gemstone. Industrial applications include watch crystals, high-durability windows, and abrasive compounds due to extreme hardness.

Geological facts

Sapphire is the second hardest natural substance on Earth. While blue is most famous, sapphires occur in every color except red (which is classified as ruby).

Field identification & locations

Identify by its ability to scratch almost all other minerals, its high density (feels heavy for its size), and deep saturated color. Commonly sourced from Sri Lanka, Madagascar, Myanmar, and Montana.

Other mineral specimens

See all

Gneiss or Schist

Gneiss or Mica Schist with Garnet

Metamorphic

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Tumbled granite

Granite, a coarse-grained felsic intrusive igneous rock

igneous

Epidote

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

metamorphic

Pegmatite with Tourmaline and Quartz

Igneous Pegmatite

igneous

Granite

Granite (Phaneritic intrusive igneous rock)

igneous