mineral

Carborundum

Silicon Carbide (SiC)

Hardness: 9-9.5 (Mohs scale), Color: iridescent black, blue, purple, or green, Luster: Metallic to sub-metallic, Crystal Structure: Hexagonal (rhombohedral), Cleavage: None, Specific Gravity: 3.21

Hardness: 9-9

Identified May 30, 2026More mineral →

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Physical properties

Hardness: 9-9.5 (Mohs scale), Color: iridescent black, blue, purple, or green, Luster: Metallic to sub-metallic, Crystal Structure: Hexagonal (rhombohedral), Cleavage: None, Specific Gravity: 3.21

Formation & geological history

While naturally occurring as the extremely rare mineral moissanite in meteorites and volcanic pipes, almost all large iridescent specimens are man-made. They are created via the Acheson process by heating silica sand and carbon in an electric resistance furnace at temperatures up to 2500 degrees Celsius.

Uses & applications

Extensively used as an industrial abrasive (sandpaper, cutting tools), in LED manufacturing, semiconductor electronics, car brakes, and as a popular decorative display piece for mineral collectors.

Geological facts

Silicon carbide was the first semiconductor material used in electronics. Its natural form, moissanite, is so rare that it was originally mistaken for diamond when first discovered in a meteor crater.

Field identification & locations

Identify by its extreme hardness (will scratch glass and quartz easily) and its unique rainbow-like iridescence. It is not found 'in the field' in this form; it is sourced from industrial manufacturing labs.