gemstone

Rough Diamond (Uncut Diamond)

Native Carbon (C)

Hardness: 10 on Mohs scale (hardest natural substance). Color: Colorless to pale yellow/brownish tint. Luster: Adamantine to greasy. Crystal System: Cubic/Isometric, often forming octahedral or dodecahedral crystals. Cleavage: Perfect in four directions parallel to octahedron faces. Specific Gravity: 3.52.

Hardness: 10 on Mohs scale (hardest natural substance)
Color: Colorless to pale yellow/brownish tint
Luster: Adamantine to greasy

Identified July 22, 2026More gemstone →

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Physical properties

Formation & geological history

Formed at extreme depths (150 to 200 kilometers) in Earth's mantle under immense pressure (45-60 kilobars) and temperatures (900-1300°C). Brought to the surface via deep-origin volcanic eruptions in kimberlite and lamproite pipes over billions of years.

Uses & applications

Used primarily in fine jewelry after cutting and polishing. Industrial grades are used for cutting, drilling, grinding, and polishing tools due to extreme hardness.

Geological facts

Diamonds are composed of pure carbon atoms arranged in a rigid crystal lattice. Natural rough diamonds frequently exhibit smooth octahedral crystal shapes with characteristic triangular growth marks called trigons on their faces.

Field identification & locations

Identified by extreme hardness, adamantine luster, high thermal conductivity, and classic octahedral crystal forms. Major sources include Russia, Botswana, Canada, Australia, and Angola. Note: Images showing large rough diamonds listed with high carat weights online are frequently falsified listings or synthetic/glass replicas; genuine rough diamonds of this size are subject to strict Kimberley Process certification.