Diamond (set in jewelry)
Diamond (Carbon, C)
Rock Type: mineral

Physical Properties
Hardness: 10 (Mohs scale), Color: Colorless (as shown), Luster: Adamantine, Crystal Structure: Isometric-Hexoctahedral, Cleavage: Perfect in four directions, Specific Gravity: 3.51
Formation & Geological History
Formed under high-pressure, high-temperature conditions in the Earth's mantle, typically at depths of 140 to 190 kilometers. Brought to the surface by deep-origin volcanic eruptions (kimberlite or lamproite pipes). Dating back 1 to 3.5 billion years.
Uses & Applications
Primary use in jewelry as gemstones; industrial uses include cutting, drilling, and grinding tools due to extreme hardness; high-end electronics for heat sinks.
Geological Facts
Diamonds are the hardest known natural material. The 'Cullinan' is the largest gem-quality rough diamond ever found, weighing 3,106 carats. Most natural diamonds are billions of years old.
Field Identification & Locations
Identify by extreme hardness and high refractive index (brilliance). In the field, look for octahedral crystals within kimberlite matrix. Note: This specimen is already cut and faceted for jewelry.
Identified on: 4/21/2026
Mode: Standard