gemstone

Diamond

Carbon (C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal Structure: Isometric-hexoctahedral, Cleavage: Octahedral (perfect in 4 directions), Specific Gravity: 3.51

Identified July 6, 2026More gemstone →

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Physical properties

Formation & geological history

Formed under extreme pressure and temperature in the Earth's mantle (150-250km deep) roughly 1 to 3.5 billion years ago. They are brought to the surface by deep-origin volcanic eruptions called kimberlites.

Uses & applications

Primary use in high-end jewelry (engagement rings) and industrial applications such as cutting, grinding, and drilling due to its unrivaled hardness.

Geological facts

Diamonds are the hardest known natural material. Only another diamond can scratch a diamond. They were first recognized and mined in India at least 3,000 to 6,000 years ago.

Field identification & locations

Identified by its high refractive index, extreme hardness (scratch test against other minerals), and ability to conduct heat. Commonly found in alluvial deposits or kimberlite pipes in Russia, Botswana, and Canada.