Rough Diamond

Physical Properties

Hardness: 10 (Mohs scale); Color: Colorless to faint yellow, brown, or gray; Luster: Adamantine (diamond-like); Crystal Structure: Isometric (cubic); Cleavage: Perfect in four directions octahedral; Specific Gravity: 3.51

Formation & Geological History

Formed deep within the Earth's mantle (approx. 100 miles down) under extreme heat and pressure. Transported to the surface via deep-source volcanic eruptions called kimberlite or lamproite pipes. Most are 1 to 3.5 billion years old.

Uses & Applications

Primary use in jewelry when of gemstone quality. Industrial grade diamonds are used for cutting, grinding, drilling, and as abrasives due to extreme hardness. Also used in high-performance electronics and heat sinks.

Geological Facts

Diamonds are the hardest natural substance known on Earth. Their name comes from the Greek word 'adamas', meaning unbreakable. They are the only gemstone made of a single element: Carbon.

Field Identification & Locations

Identify in the field by its extreme hardness (cannot be scratched by any other mineral), greasy luster when rough, and crystal shape (typically octahedrons). Commonly found in kimberlite pipes or alluvial deposits in riverbeds.

Identified on: 4/17/2026

Mode: Standard