gemstone

Diamond

Carbon (C)

Hardness: 10 (Mohs scale), Color: Colorless (in this specimen), Luster: Adamantine, Crystal Structure: Cubic (Isometric), Cleavage: Perfect in four directions (octahedral), Specific Gravity: 3.52

Identified July 10, 2026More gemstone →

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Physical properties

Hardness: 10 (Mohs scale), Color: Colorless (in this specimen), Luster: Adamantine, Crystal Structure: Cubic (Isometric), Cleavage: Perfect in four directions (octahedral), Specific Gravity: 3.52

Formation & geological history

Formed under extreme pressure and temperature in the Earth's mantle, approximately 100 to 150 miles deep. They are brought to the surface by deep-origin volcanic eruptions known as kimberlite or lamproite pipes. Most diamonds are 1 to 3.5 billion years old.

Uses & applications

Primary use in jewelry as a gemstone; also used in industry for cutting, grinding, and drilling tools due to extreme hardness. Used in high-pressure scientific experiments and heat sinks.

Geological facts

Diamond is the hardest naturally occurring substance on Earth. It is composed of a single element: Carbon. The name comes from the Greek word 'adamas', meaning invincible or unbreakable.

Field identification & locations

Identify by extreme hardness (scratches all other minerals), high refractive index (brilliance), and thermal conductivity. Often found in kimberlite pipes or alluvial deposits in rivers and shorelines.