mineral

Rough Diamond

Diamond (pure Carbon, C)

Hardness: 10 (Mohs scale), Color: Pale yellow (Cape series), Luster: Adamantine to greasy (in rough state), Crystal structure: Isometric-Hexoctahedral, Cleavage: Perfect octahedral, Specific gravity: 3.51

Identified March 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed under high-pressure, high-temperature conditions in the Earth's mantle (100+ miles deep) over 1 to 3 billion years ago. Brought to the surface via kimberlite or lamproite volcanic eruptions.

Uses & applications

Primary use in high-end jewelry (once cut and polished) and extensive industrial applications including cutting, grinding, and drilling due to extreme hardness.

Geological facts

Diamonds are the hardest known natural material. While often associated with 'colorless' gems, most natural rough diamonds are slightly yellowish or brownish. The 'adamantine' luster of a diamond is unique and a key diagnostic feature.

Field identification & locations

Identify by extreme hardness (scratches all other minerals), greasy surface texture, and crystal habit (octahedrons are common). Often found in alluvial deposits or kimberlite pipes in regions like South Africa, Russia, Canada, and Australia.