Quartz

Physical Properties

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

Formation & Geological History

Forms in a wide variety of environments, most commonly by crystallizing from cooling magma or precipitating from hydrothermal veins. It is a major constituent of continental crust and can be found in rocks of all geological ages.

Uses & Applications

Used extensively in glassmaking, electronics (piezoelectric properties), abrasives, construction, and as gemstones or decorative pieces.

Geological Facts

Quartz is one of the most abundant minerals in Earth's crust. It is highly resistant to both chemical and physical weathering, which is why it is often the primary component of river and beach sand.

Field Identification & Locations

Identify in the field by its hardness (it can scratch glass and steel knives) and its lack of cleavage (it breaks in irregular or curved surfaces). Look for it in veins within granite or as individual crystals in cavities.

Identified on: 4/22/2026

Mode: Standard