gemstone

Diamond

Carbon (C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal system: Isometric/Cubic, Cleavage: Perfect octahedral, Specific gravity: 3.52

Identified July 10, 2026More gemstone →

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Physical properties

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal system: Isometric/Cubic, Cleavage: Perfect octahedral, Specific gravity: 3.52

Formation & geological history

Formed under extreme pressure and high temperature conditions (900–1,300 degrees Celsius) in the Earth's mantle at depths of 140–190 kilometers, brought to the surface by deep-origin volcanic eruptions (kimberlites) over millions to billions of years.

Uses & applications

Extensively used in fine jewelry (engagement rings, necklaces) due to its brilliance and hardness; also used in industry for cutting, drilling, grinding, and polishing tools.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. Its name is derived from the Greek word 'adamas', meaning invincible or indestructible. Most natural diamonds are between 1 billion and 3.5 billion years old.

Field identification & locations

Identified by its extreme hardness (cannot be scratched by any other mineral), high refractive index resulting in intense sparkle, and distinctive crystal forms like octahedrons. Found primarily in pipes of kimberlite and lamproite or in alluvial deposits.