mineral

Quartz (Milky or Smoky)

Silicon Dioxide (SiO2)

Hardness: 7 Mohs scale; Color: Semi-translucent brownish-white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 Mohs scale
Color: Semi-translucent brownish-white
Luster: Vitreous to greasy

Identified July 7, 2026More mineral →

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Physical properties

Hardness: 7 Mohs scale; Color: Semi-translucent brownish-white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in diverse geological environments, primarily cooling from silica-rich magma or precipitation from hydrothermal veins. It is a major constituent of continental crust.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), jewelry, sandpaper, and as a popular specimen for crystal collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek word 'krystallos', meaning ice, as it was once believed to be permanently frozen ice.

Field identification & locations

Identify by its hardness (will scratch glass) and lack of cleavage planes. Found worldwide in nearly all rock types. This specific specimen shows a grainy, crystalline texture common in vein quartz or quartzite fragments.