Diamond (as set in a gold ring)

Physical Properties

Hardness: 10 (Mohs scale); Color: Colorless/White (in this specimen); Luster: Adamantine; Crystal Structure: Isometric (Cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.51-3.53

Formation & Geological History

Formed under high-pressure, high-temperature conditions in the Earth's mantle, approximately 100 miles underground, and transported to the surface by kimberlite and lamproite volcanic eruptions. Most are 1-3.5 billion years old.

Uses & Applications

Primary use in high-end jewelry and engagement rings; industrial grade diamonds are used for cutting, drilling, and grinding tools due to extreme hardness.

Geological Facts

Diamond is the hardest natural substance known to man. It is a polymorph of carbon, meaning it has the same chemical composition as graphite (pencil lead) but an entirely different crystal structure.

Field Identification & Locations

Identify in the field by its extreme hardness (cannot be scratched by any other material), high refractive index, and thermal conductivity. Commonly found in secondary alluvial deposits or primary kimberlite pipes located in ancient cratons (Africa, Russia, Canada, Australia).

Identified on: 4/26/2026

Mode: Standard