gemstone

Diamond

Carbon (C)

Hardness: 10 (Mohs scale), Color: Colorless (in this specimen), Luster: Adamantine, Crystal Structure: Isometric-Hexoctahedral, Cleavage: Perfect in four directions, Specific Gravity: 3.52

Identified July 6, 2026More gemstone →

Explore Diamond in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 10 (Mohs scale), Color: Colorless (in this specimen), Luster: Adamantine, Crystal Structure: Isometric-Hexoctahedral, Cleavage: Perfect in four directions, Specific Gravity: 3.52

Formation & geological history

Formed under high-pressure, high-temperature conditions in Earth's mantle, approximately 90 to 120 miles deep, and brought to the surface by kimberlite eruptions. Ages range from 1 to 3.5 billion years.

Uses & applications

Extensively used in jewelry, and for industrial applications such as cutting, drilling, and grinding due to its extreme hardness.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. Its name is derived from the Greek word 'adamas', meaning unbreakable or invincible.

Field identification & locations

Identified by its high refractive index (brilliance), dispersion (fire), and hardness. Testing with a diamond selector or looking for 'loupe-clean' inclusions can help differentiate from simulants like Cubic Zirconia.