mineral

Diamond

Diamond (C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown (jewelry grade), Luster: Adamantine, Crystal Structure: Isometric-Hexoctahedral, Cleavage: Perfect in four directions (octahedral), Specific Gravity: 3.52

Identified May 4, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed under high-pressure, high-temperature conditions in the Earth's mantle, approximately 100 miles below the surface, and brought upward by deep-source volcanic eruptions called kimberlite pipes. Most natural diamonds are between 1 billion and 3.5 billion years old.

Uses & applications

Primarily used in jewelry; industrial use as abrasives and for cutting/drilling tools due to extreme hardness.

Geological facts

Diamonds are the hardest known natural material on Earth and are composed of pure carbon arranged in a crystal lattice. The word 'diamond' comes from the ancient Greek 'adamas', meaning unbreakable.

Field identification & locations

Identify in jewelry by high dispersion (fire), extreme hardness, and metal settings. In nature, they are often found in kimberlite or lamproite rocks or secondary alluvial deposits. For collectors, look for the 'Four Cs': Cut, Color, Clarity, and Carat weight.