mineral

Quartz (Milky or Druzy variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to translucent
Luster: Vitreous to greasy

Identified May 7, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through hydrothermal processes where silica-rich fluids cool in vein cavities or volcanic vesicles. Can occur across various geological ages from Precambrian to recent.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), abrasives, and as semi-precious gemstones in jewelry or decorative carvings.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it often remains as sand on beaches.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and hexagonal crystal shapes if present. Commonly found in quartz veins and granitic rocks worldwide.

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