mineral

Diamond (Uncut Crystal)

Carbon (C)

Hardness: 10 (Mohs scale), Color: Colorless to faint yellow/brown, Luster: Adamantine, Crystal Structure: Cubic (often octahedral as seen in the specimen), Cleavage: Perfect in four directions (octahedral), Specific Gravity: 3.52

Identified April 12, 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 deep within the Earth's mantle (over 150km deep) under extreme pressure and high temperatures. They are brought to the surface via deep-seated volcanic eruptions called kimberlite pipes. Most diamond deposits are between 1 billion and 3.5 billion years old.

Uses & applications

Used primarily in jewelry (after cutting and polishing) and industrial applications including cutting, drilling, and grinding tools due to its extreme hardness. Also used in high-pressure scientific research and high-performance electronics.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. It is composed of a single element (carbon) arranged in an extremely strong tetrahedral crystal structure. The Cullinan Diamond is the largest gem-quality rough diamond ever found.

Field identification & locations

Identify in the field by its extreme hardness (cannot be scratched by any other mineral), high thermal conductivity, and its characteristic octahedral or dodecahedral natural crystal shape. Found in kimberlite pipes or alluvial deposits (river beds/ocean floors).