Diamond (as featured in jewelry)

Physical Properties

Hardness: 10 (Mohs scale); Color: Colorless (in this specimen), can range from yellow to blue; Luster: Adamantine; Crystal Structure: Isometric-Hexoctahedral; Specific Gravity: 3.51-3.53; Cleavage: Perfect octahedral.

Formation & Geological History

Formed under high-pressure, high-temperature conditions in the Earth's mantle, approximately 90 to 120 miles deep. They are brought to the surface by kimberlite eruptions. Most are 1 to 3 billion years old.

Uses & Applications

Primary use is in high-end jewelry (engagement rings, bracelets). Industrially used as abrasives, in cutting tools, drill bits, and as heat sinks in electronics due to high thermal conductivity.

Geological Facts

Diamond is the hardest natural substance known to man. Rare 'fancy color' diamonds can cost millions per carat. The word comes from the Greek 'adamas', meaning unbreakable.

Field Identification & Locations

Identify by testing thermal conductivity or using a loupe to check for natural inclusions and the 'fire' (dispersion). Common sources include Russia, Botswana, and Canada. For collectors, the 4 Cs (Cut, Color, Clarity, Carat) are the gold standard.

Identified on: 4/27/2026

Mode: Standard