Quartz (Quarzite or Massive Quartz vein)

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white to tan/grey with iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed through the recrystallization of quartz-rich sandstone under intense heat and pressure (metamorphism), or as a hydrothermal vein deposit from silica-rich fluids in cracks within the earth's crust.

Uses & Applications

Used in construction as crushed stone, in the manufacture of glass and ceramics, as an abrasive, and sometimes in landscaping or as a collector specimen.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. It is extremely resistant to chemical and physical weathering, which is why it often remains as large boulders in riverbeds or on the ground long after other minerals have eroded.

Field Identification & Locations

Identify in the field by its inability to be scratched by a steel knife and its lack of cleavage (it breaks in irregular, curved 'glass-like' flakes). Commonly found in mountain ranges and riverbeds globally.

Identified on: 4/29/2026

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