gemstone

Diamond

Natural Diamond (Carbon, C)

Hardness: 10 Mohs; Color: Colorless (D-H range); Luster: Adamantine; Crystal Structure: Isometric (Cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.52

Hardness: 10 Mohs
Color: Colorless (D-H range)
Luster: Adamantine

Identified July 10, 2026More gemstone →

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Physical properties

Hardness: 10 Mohs; Color: Colorless (D-H range); Luster: Adamantine; Crystal Structure: Isometric (Cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.52

Formation & geological history

Formed under extreme pressure and temperature in the Earth's mantle, 100-200 miles deep, over 1-3 billion years ago; brought to surface via kimberlite volcanic eruptions.

Uses & applications

Primary use in high-end jewelry (engagement rings) and industrial applications for cutting, grinding, and drilling due to extreme hardness.

Geological facts

Diamonds are the hardest known natural substance. The Hope Diamond is one of the most famous colorless-to-blue specimens in history.

Field identification & locations

Identify by testing thermal conductivity or using a diamond loupe to check for natural inclusions and the 'adamantine' luster that synthetic glass lacks. Found primarily in pipes of kimberlite.