Diamond

Physical Properties

Hardness: 10 (Mohs scale); Color: Colorless to faint yellow/brown (in this specimen); Luster: Adamantine; Crystal Structure: Isometric-hexoctahedral (Cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.52

Formation & Geological History

Formed under high pressure and temperature conditions in the Earth's mantle, approximately 150-250 kilometers deep. Most natural diamonds are between 1 billion and 3.5 billion years old and are brought to the surface by kimberlite and lamproite volcanic eruptions.

Uses & Applications

Primarily used in jewelry (engagement rings) and high-end collecting. Industrially used for cutting, drilling, and grinding tools due to extreme hardness.

Geological Facts

Diamond is the hardest naturally occurring substance on Earth. While they are famous as gemstones, 80% of mined diamonds are used for industrial purposes. They are composed of a single element: Carbon.

Field Identification & Locations

Identify by extreme hardness (can scratch all other minerals), high refractive index (brilliance/fire), and thermal conductivity. Look for 'trigons' (triangular growth pits) on raw crystal surfaces. Found in kimberlite pipes or alluvial deposits.

Identified on: 4/20/2026

Mode: Standard