mineral

Diamond

Diamond (C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown (jewelry grade), Luster: Adamantine, Crystal Structure: Isometric-hexoctahedral, Cleavage: Octahedral, Specific Gravity: 3.52

Identified January 23, 2026More mineral →

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Physical properties

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown (jewelry grade), Luster: Adamantine, Crystal Structure: Isometric-hexoctahedral, Cleavage: Octahedral, Specific Gravity: 3.52

Formation & geological history

Formed under high temperature and pressure conditions in the Earth's mantle (150-250 km deep), then transported to the surface via deep-source volcanic eruptions called kimberlite pipes. Most are 1 billion to 3.5 billion years old.

Uses & applications

Primary use in jewelry as gemstones; industrial uses include cutting, drilling, and grinding tools due to extreme hardness.

Geological facts

Diamond is the hardest naturally occurring substance known. The name is derived from the Greek 'adamas', meaning invincible. Famous specimens include the Cullinan and the Hope Diamond.

Field identification & locations

Identified by its extreme hardness (cannot be scratched by any other mineral) and high refractive index. Commonly found in kimberlite and lamproite pipes or in alluvial deposits (riverbeds).