gemstone

Diamond

Carbon (C)

Hardness: 10 on Mohs scale; Color: Colorless to yellow, brown, blue, pink; Luster: Adamantine; Crystal structure: Isometric (cubic); Cleavage: Perfect in four directions; Specific gravity: 3.50-3.53

Hardness: 10 on Mohs scale
Color: Colorless to yellow, brown, blue, pink
Luster: Adamantine

Identified August 3, 2026More gemstone →

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Physical properties

Hardness: 10 on Mohs scale; Color: Colorless to yellow, brown, blue, pink; Luster: Adamantine; Crystal structure: Isometric (cubic); Cleavage: Perfect in four directions; Specific gravity: 3.50-3.53

Formation & geological history

Formed under high-pressure and high-temperature conditions in the Earth's mantle, typically at depths of 150 to 250 kilometers, and brought to the surface by deep-seated volcanic eruptions of kimberlite and lamproite magmas. Geological age ranges from 1 to 3.5 billion years.

Uses & applications

Widely used in high-end fine jewelry, engagement rings, and various industrial applications including cutting, grinding, drilling, and polishing tools due to its extreme hardness.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. Despite being made of the same element as soft graphite, its tight covalent bonding gives it incomparable strength. The Cullinan Diamond, found in South Africa in 1905, is the largest gem-quality rough diamond ever found.

Field identification & locations

Can be identified by its extreme hardness, high refractive index, and adamantine luster. Commonly found in alluvial deposits and primary kimberlite pipes in countries such as Russia, Botswana, Canada, and South Africa.