mineral

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Hardness: 9-9.5 on Mohs scale; Color: Iridescent, black, green, or blue; Luster: Submetallic to adamantine; Crystal structure: Hexagonal (wurtzite) or cubic; Specific Gravity: 3.21.

Hardness: 9-9
Color: Iridescent, black, green, or blue
Luster: Submetallic to adamantine

Identified June 28, 2026More mineral →

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Physical properties

Hardness: 9-9.5 on Mohs scale; Color: Iridescent, black, green, or blue; Luster: Submetallic to adamantine; Crystal structure: Hexagonal (wurtzite) or cubic; Specific Gravity: 3.21.

Formation & geological history

While the extremely rare mineral moissanite is natural, nearly all visible specimens are man-made. They are formed via the Acheson process, which involves heating silica sand and carbon to high temperatures in an electric resistance furnace.

Uses & applications

Used primarily as an industrial abrasive for grinding and cutting, in semiconductor electronics, and as a popular decorative specimen for collectors. In its gem form, it is sold as Moissanite.

Geological facts

Naturally occurring silicon carbide (moissanite) is so rare that it was first discovered in a meteor crater. The iridescent 'rainbow' sheen on commercial specimens is caused by a thin layer of silicon dioxide that forms on the surface.

Field identification & locations

Identify by its extreme hardness (will scratch almost anything except diamond), iridescent metallic colors, and brittle, crunchy texture. It is not found in the field naturally; it is typically purchased from gift shops or mineral dealers.