mineral

Diamond

Diamond (pure Carbon, C)

Hardness: 10 (Mohs scale); Color: Typically colorless but can be yellow, brown, or blue; Luster: Adamantine; Crystal Structure: Isometric-Hexoctahedral; Cleavage: Perfect octahedral; Specific Gravity: 3.52

Hardness: 10 (Mohs scale)
Color: Typically colorless but can be yellow, brown, or blue
Luster: Adamantine

Identified January 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed under high-pressure, high-temperature conditions in the Earth's mantle, approximately 100 miles below the surface. They are brought to the surface through deep-source volcanic eruptions known as kimberlite or lamproite pipes.

Uses & applications

Predominantly used in jewelry for engagement rings and high-end fashion. Industrially used for cutting, drilling, and grinding tools due to extreme hardness, as well as in heat sinks for electronics.

Geological facts

Diamonds are the hardest known natural substance. The largest gem-quality diamond ever found was the Cullinan Diamond, discovered in 1905, weighing 3,106 carats.

Field identification & locations

Field identification is difficult as they are rare in their primary source; however, they can be found in alluvial deposits (river gravels) by their high luster and crystal shape. Collectors look for the characteristic octahedral shape and extreme hardness—it will scratch any other material.