Quartz

Physical Properties

Hardness: 7 on Mohs scale; Color: Colorless, white, or smoky 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 crystallization of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust and can be found in igneous, metamorphic, and sedimentary environments across all geological ages.

Uses & Applications

Used extensively in glassmaking, electronics (piezoelectric properties), abrasives, grit for sandpaper, construction, and as gemstones in jewelry.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. It has piezoelectric properties, meaning it can generate an electric charge in response to applied mechanical stress, which is why it is used in watches and clocks.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and conchoidal (shell-like) fracture. Commonly found in granite veins or as pebbles in stream beds.

Identified on: 5/4/2026

Mode: Standard