gemstone

Diamond

Natural Diamond (Carbon, C)

Hardness: 10 Mohs; Color: Colorless (in this specimen); Luster: Adamant; Crystal Structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.52

Hardness: 10 Mohs
Color: Colorless (in this specimen)
Luster: Adamant

Identified July 10, 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; Color: Colorless (in this specimen); Luster: Adamant; Crystal Structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.52

Formation & geological history

Formed under extreme pressure and temperature in the Earth's mantle (over 150 km deep), then transported to the surface via kimberlite or lamproite volcanic eruptions. Most natural diamonds are between 1 and 3.5 billion years old.

Uses & applications

Used extensively in fine jewelry (engagement rings) and high-end industrial applications such as cutting, grinding, and drilling due to its extreme hardness.

Geological facts

Diamond is the hardest natural substance on Earth. Its name comes from the Greek word 'adamas', meaning unbreakable or invincible. Diamond is a polymorph of graphite; both are made of pure carbon but have different crystal structures.

Field identification & locations

Identified by its extreme hardness (cannot be scratched by any other mineral), high refractive index, and specific gravity. Common mining locations include Russia, Botswana, Canada, and South Africa.