mineral

Rough Diamond

Diamond (pure carbon / C)

Hardness: 10 (Mohs scale); Color: Grayish-clear/translucent; Luster: Adamantine (greasy in rough state); Crystal structure: Isometric-hexoctahedral; Cleavage: Perfect in four directions; Specific Gravity: 3.5–3.53.

Hardness: 10 (Mohs scale)
Color: Grayish-clear/translucent
Luster: Adamantine (greasy in rough state)

Identified March 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed under extreme pressure and high temperature (deep mantle, 150-250km deep) roughly 1 to 3.5 billion years ago. Brought to the surface via kimberlite or lamproite volcanic eruptions.

Uses & applications

Primary use in high-end jewelry (when cut/polished); significant industrial uses in cutting, drilling, and grinding tools due to extreme hardness.

Geological facts

Diamonds are the hardest known natural substance. The specimen in the image appears to be a 'maccle' or a rough industrial-grade diamond, showing the characteristic waxy/greasy luster and octahedral-like shape common in uncut stones.

Field identification & locations

Identify in the field by its high specific gravity (feels heavy for its size), greasy surface luster, and ability to scratch any other mineral. Commonly found in kimberlite pipes or alluvial deposits in Africa, Russia, and Canada.