mineral

Carbonado (Black Diamond)

Carbonado (Polycrystalline Diamond)

Hardness: 10 (Mohs scale), Color: Black or dark grey, Luster: Adamantine to greasy, Crystal structure: Cubic (polycrystalline aggregate), Cleavage: None (unlike monocrystalline diamond), Specific gravity: 3.1 to 3.4

Identified June 8, 2026More mineral →

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Physical properties

Formation & geological history

Found in alluvial deposits in Brazil and Central African Republic. Origin theories include formation in stellar supernovae or high-pressure impacts on Earth. Estimated age is 2.6 to 3.8 billion years old.

Uses & applications

Used primarily in industrial applications for abrasive tools, drill bits, and as unique gemstones in jewelry.

Geological facts

Carbonado is exceptionally tough compared to conventional diamonds because its polycrystalline structure prevents the propagation of cleavage fractures. It contains traces of nitrogen and hydrogen that suggest an extraterrestrial origin.

Field identification & locations

Identify by its dark, porous (vesicular) appearance and extreme hardness. Look for a metallic or glassy sheen on broken edges. Commonly found in river sediments in South America and Africa.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

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Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic