mineral

Silicon

Element Si

Hardness: 7 on Mohs scale; Color: Gray with a metallic, bluish-silvery luster; Crystal structure: Diamond cubic; Cleavage: Octahedral; Specific gravity: 2.33.

Hardness: 7 on Mohs scale
Color: Gray with a metallic, bluish-silvery luster

Identified June 15, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Gray with a metallic, bluish-silvery luster; Crystal structure: Diamond cubic; Cleavage: Octahedral; Specific gravity: 2.33.

Formation & geological history

Synthetically grown through the Czochralski process or the Float-zone process from high-purity silica (sand). While silicon is the second most abundant element in the Earth's crust, it is never found in its pure elemental form naturally.

Uses & applications

Used primarily in the semiconductor industry for making computer chips, transistors, and integrated circuits. Also used in solar panels (photovoltaics) and as an alloying agent in aluminum and steel.

Geological facts

Silicon is not a metal but a metalloid. In its pure crystalline form, it is very brittle. It is the basis of the entire Silicon Valley tech industry. Pure specimens like this are often 'leftovers' or slag from industrial purification processes.

Field identification & locations

Identify by its surprisingly light weight (low density), metallic gray luster, and very sharp, glass-like (conchoidal) fracture. It is rarely found in the 'wild' unless near an industrial facility or discarded by a hobbyist.