gemstone

Diamond

Carbon (C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal Structure: Cubic, Specific Gravity: 3.52

Luster: Adamantine, Crystal Structure: Cubic, Specific Gravity: 3

Identified July 20, 2026More gemstone →

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Physical properties

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal Structure: Cubic, Specific Gravity: 3.52

Formation & geological history

Formed under high-pressure, high-temperature conditions in Earth's mantle, approximately 100 miles underground, and transported to the surface via deep-source volcanic eruptions called kimberlite pipes.

Uses & applications

Extensively used in jewelry; also used in industrial applications for cutting, grinding, and drilling due to its unparalleled hardness.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. Most diamonds are between 1 billion and 3.5 billion years old.

Field identification & locations

Identified by its high refractive index, extreme hardness (scratches all other materials), and thermal conductivity. Commonly found in South Africa, Russia, Canada, and Australia.