gemstone

Diamond

Carbon (C)

Hardness: 10 on the Mohs scale; Color: Typically colorless or white, but can be yellow, brown, blue, green, pink; Luster: Adamantine; Crystal Structure: Isometric (cubic); Cleavage: Perfect octahedral cleavage in four directions; Specific Gravity: 3.51 - 3.53

Hardness: 10 on the Mohs scale
Luster: Adamantine

Identified August 2, 2026More gemstone →

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Physical properties

Formation & geological history

Formed under high-pressure and high-temperature conditions (approximately 900 to 1,300 degrees Celsius and 45 to 60 kilobars) in the Earth's mantle, typically at depths of 140 to 190 kilometers. Brought to the surface via deep-source volcanic eruptions (kimberlite and lamproite pipes), primarily during the Precambrian era and later.

Uses & applications

Widely used in fine jewelry and engagement rings, as well as in industrial cutting, grinding, drilling, and polishing tools due to its extreme hardness.

Geological facts

Diamond is the hardest known natural material on Earth. The largest gem-quality diamond ever found is the Cullinan Diamond, weighing 3,106 carats, discovered in South Africa in 1905.

Field identification & locations

Identified by its adamantine luster, lack of scratching by other minerals, high thermal conductivity, and high dispersion (fire). Commonly found in South Africa, Russia, Canada, Botswana, and Australia.