gemstone

Diamond

Carbon (C)

Hardness: 10 (Mohs scale); Color: Colorless (in this specimen); Luster: Adamantine; Crystal Structure: Isometric-hexoctahedral; Specific Gravity: 3.51

Hardness: 10 (Mohs scale)
Color: Colorless (in this specimen)
Luster: Adamantine

Identified July 10, 2026More gemstone →

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Physical properties

Hardness: 10 (Mohs scale); Color: Colorless (in this specimen); Luster: Adamantine; Crystal Structure: Isometric-hexoctahedral; Specific Gravity: 3.51

Formation & geological history

Formed under high pressure and temperature conditions in the Earth's mantle, approximately 100 miles below the surface, usually between 1 to 3.5 billion years ago. They are brought to the surface via kimberlite or lamproite volcanic pipes.

Uses & applications

Used extensively in fine jewelry, for industrial cutting and grinding tools due to its extreme hardness, and in high-tech optics or heat sinks.

Geological facts

Diamond is the hardest natural substance known on Earth. Many diamonds are significantly older than the dinosaurs. The largest gem-quality diamond ever found was the Cullinan, weighing 3,106 carats.

Field identification & locations

Identified in the field by its extreme hardness (cannot be scratched by any other mineral), high refractive index (brilliance), and specific gravity. Often sorted from river gravels or mined from kimberlite pipes in regions like South Africa, Russia, and Canada.