mineral

Diamond

Diamond (pure Carbon, C)

Hardness: 10 (Mohs scale); Color: Colorless (in this specimen), can range through fancy colors; Luster: Adamantine; Crystal Structure: Isometric-Hexoctahedral (cubic); Cleavage: Perfect in four directions forming octahedrons; Specific Gravity: 3.52

Hardness: 10 (Mohs scale)
Color: Colorless (in this specimen), can range through fancy colors
Luster: Adamantine

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed under extreme high pressure and temperature in the Earth's mantle, typically at depths of 140–190 kilometers. They are brought to the surface through deep-origin volcanic eruptions in pipes of kimberlite or lamproite rock. Most natural diamonds are between 1 billion and 3.5 billion years old.

Uses & applications

Primary use is in high-end jewelry (rings, earrings, necklaces). In industry, it is used for cutting, drilling, and grinding tools due to its extreme hardness. Also used in heat sinks for specialized electronics.

Geological facts

Diamond is the hardest known natural substance. The word comes from the Greek 'adamas', meaning unbreakable. It is the only gemstone made of a single element (Carbon). The largest diamond ever found was the Cullinan, weighing 3,106 carats.

Field identification & locations

In the field, it is identified by its high luster, its ability to scratch all other minerals, and its presence in kimberlite pipes or alluvial deposits. For faceted stones as seen in the image, professional gemologists use loupes to check for inclusions, thermal conductivity probes, and refractometers.