mineral

Silicon

Element Si

Hardness: 7 Mohs; Color: Metallic gray/blue-tinted; Luster: Submetallic to vitreous; Crystal Structure: Cubic; Specific Gravity: 2.33; Texture: Polycrystalline or vitreous-like cleavage.

Hardness: 7 Mohs
Color: Metallic gray/blue-tinted
Luster: Submetallic to vitreous

Identified June 11, 2026More mineral →

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Physical properties

Hardness: 7 Mohs; Color: Metallic gray/blue-tinted; Luster: Submetallic to vitreous; Crystal Structure: Cubic; Specific Gravity: 2.33; Texture: Polycrystalline or vitreous-like cleavage.

Formation & geological history

Silicon is incredibly common in the Earth's crust as silicates, but native silicon (pure element) is extremely rare in nature. This specimen is most likely a synthetic industrial polycrystalline silicon produced via the Czochralski or Siemens process from silica sand.

Uses & applications

Primary use is in the semiconductor industry for making computer chips, transistors, and solar cells. It is also used as an alloying agent in aluminum production and for making silicones.

Geological facts

While it is the second most abundant element in the Earth's crust by mass (after oxygen), it is almost never found 'native' or pure in nature; it must be refined from minerals like quartz.

Field identification & locations

Identify by its surprisingly light weight (low density), bright metallic gray sheen, and characteristic brittle fracture that looks like broken glass. It is commonly sold as a curiosity or educational specimen in rock shops.