Diamond

Physical Properties

Hardness: 10 (Mohs scale); Color: Colorless (as shown), yellow, brown, or blue; Luster: Adamantine; Crystal structure: Isometric-hexoctahedral; Cleavage: Perfect in four directions forming octahedrons; Specific gravity: 3.51

Formation & Geological History

Formed under high-pressure, high-temperature conditions at depths of 140 to 190 kilometers in the Earth's mantle. Delivered to the surface through deep-origin volcanic eruptions called kimberlites.

Uses & Applications

Primary use in jewelry as a gemstone and industrial use as abrasives, cutting tools, and thermal conductors.

Geological Facts

Diamonds are the hardest known natural material on Earth. Most natural diamonds were formed over 1 billion years ago, with some specimens dating back 3.3 billion years.

Field Identification & Locations

Identify by its exceptional brilliance (fire), hardness (will scratch any other material), and specific gravity. Commonly found in kimberlite pipes or alluvial deposits in Africa, Russia, Canada, and Australia.

Identified on: 5/1/2026

Mode: Standard