mineral

Diamond

Diamond (pure Carbon, C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown (can be fancy colors), Luster: Adamantine, Crystal Structure: Cubic/Isometric, Cleavage: Octahedral, Specific Gravity: 3.52

Identified June 28, 2026More mineral →

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Physical properties

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown (can be fancy colors), Luster: Adamantine, Crystal Structure: Cubic/Isometric, Cleavage: Octahedral, Specific Gravity: 3.52

Formation & geological history

Formed under high pressure and high temperature in the Earth's mantle (approx. 150-200 km deep) and brought to the surface by kimberlite eruptions. Most are 1 to 3.5 billion years old.

Uses & applications

Used extensively in fine jewelry (engagement rings, etc.) and industrially for cutting, grinding, and drilling due to its extreme hardness.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. It is composed of a single element: Carbon. The Hope Diamond and the Cullinan are two of the world's most famous specimens.

Field identification & locations

Identify by its hardness (scratches all other minerals), high refractive index (brilliance), and high thermal conductivity. Found in kimberlite pipes or secondary alluvial deposits.