Quartz (Clear Quartz/Rock Crystal)

Physical Properties

Hardness: 7 on Mohs scale; Color: Colorless to transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & Geological History

Formed from cooling silica-rich magma or from hydrothermal veins. It can be found in all types of geological environments and spans nearly all geological ages due to its stability.

Uses & Applications

Used in glass manufacturing, electronics (piezoelectric properties), optics, construction as an abrasive, and widely used in jewelry and gemstone collecting.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Herkimer Diamonds' are a famous double-terminated variety of clear quartz. It was historically used to make crystal balls.

Field Identification & Locations

Identified in the field by its hardness (scratches glass), glass-like appearance, and lack of cleavage (it breaks into curved, shell-like surfaces). Found globally in pegmatites, veins, and as sand.

Identified on: 5/19/2026

Mode: Standard