mineral

Quartz (Milky or Smoky Quartz)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: White to greyish-brown; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to greyish-brown
Luster: Vitreous (glassy) to greasy

Identified March 26, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to greyish-brown; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of magma in hydrothermal veins or as a component of igneous rocks like granite. Can range from hundreds of millions to billions of years old, commonly found in pegmatites and metamorphic environments.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), construction as an aggregate, and as a gemstone/decorative specimen for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is a key indicator of silica-rich environments and is highly resistant to chemical and physical weathering.

Field identification & locations

Identify in the field by its hardness (will easily scratch glass), lack of cleavage, and translucent appearance. Found worldwide in mountainous regions, riverbeds, and as inclusions in granite outcrops.

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