Sapphire

Physical Properties

Hardness: 9 (Mohs scale), Color: Blue (though can be other colors), Luster: Vitreous to sub-adamantine, Crystal structure: Trigonal, Specific gravity: 3.95-4.03

Formation & Geological History

Formed in metamorphic or igneous rocks. Found in alluvial deposits.

Uses & Applications

Predominantly used in jewelry due to its hardness and beauty. Historically used for protective value and status.

Geological Facts

Sapphire is one of the four precious stones. The blue color is typically caused by trace amounts of iron and titanium.

Field Identification & Locations

Identified by its high hardness (scratches almost everything except diamond), bright blue color, and specific crystal shapes when rough. Often found in Sri Lanka, Madagascar, Australia, and Montana (USA).

Identified on: 4/27/2026

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