mineral

Rough Black Diamond (Bort / Carbonado)

Diamond (C)

Hardness: 10 (Mohs scale); Color: Black, opaque; Luster: Adamantine to sub-metallic; Crystal Structure: Isometric (cubic); Specific Gravity: 3.5–3.53

Hardness: 10 (Mohs scale)
Color: Black, opaque
Luster: Adamantine to sub-metallic

Identified July 17, 2026More mineral →

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Physical properties

Hardness: 10 (Mohs scale); Color: Black, opaque; Luster: Adamantine to sub-metallic; Crystal Structure: Isometric (cubic); Specific Gravity: 3.5–3.53

Formation & geological history

Formed deep under high pressure and temperature conditions in the Earth's mantle, approximately 1 to 3 billion years ago. Carbonados specifically are hypothesized by some to have extraterrestrial origins via supernovae.

Uses & applications

Primarily used in industrial cutting, drilling, and grinding tools. High-quality specimens are used in fashion jewelry as 'black diamonds' after cutting and polishing.

Geological facts

Black diamonds are the toughest form of natural diamond. Unlike clear diamonds which are a single crystal, carbonados are polycrystalline, consisting of many tiny diamonds fused together.

Field identification & locations

Identify by its extreme hardness (cannot be scratched by any other material) and its unique metallic/greasy luster. Major deposits are found in Brazil and the Central African Republic.