mineral

Carborundum (Silicon Carbide)

Silicon Carbide (SiC)

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

Hardness: 9-9

Identified June 13, 2026More mineral →

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Physical properties

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

Formation & geological history

Synthetically produced in an electric resistance furnace (Acheson process) by heating silica sand and carbon at temperatures over 2500°C. While it occurs naturally as the extremely rare mineral moissanite, commercial specimens are man-made.

Uses & applications

Used as an abrasive in grinding wheels and sandpapers, as a refractory material in kiln furniture, in semiconductor electronics, and as decorative display specimens.

Geological facts

Carborundum was first produced by Edward Goodrich Acheson in 1891 while he was attempting to synthesize diamonds. It is one of the hardest known substances, surpassed mostly by diamonds and boron nitride.

Field identification & locations

Identified by its extreme hardness, oily or rainbow-like iridescence (thin-film interference), and sharp, jagged crystalline edges. It is not found in the field as an outcrop but rather in industrial settings or rock shops.