Quartz (Milky/Clear Quartz)

Physical Properties

Hardness: 7 on Mohs scale; Color: Colorless to white/milky; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & Geological History

Forms in a wide variety of environments, most commonly from the cooling of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust across all geological ages.

Uses & Applications

Used in electronics (as piezoelectric crystals), glassmaking, abrasives, construction as aggregate, and widely used in jewelry and gemstone collecting.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz, traditionally called rock crystal, is colorless and transparent, while inclusions can create various colors like amethyst or rose quartz.

Field Identification & Locations

Identify by its hardness (it can scratch glass and steel) and its lack of cleavage. It is found globally in riverbeds, mountains, and deserts. In the field, look for a glassy luster and a lack of flat break surfaces.

Identified on: 4/14/2026

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