Quartz (with iron oxide staining)

Physical Properties

Hardness: 7 on Mohs scale; Color: Clear to white with orange/brown rusty staining; Luster: Vitreous; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed from hydrothermal solutions or cooling magma/lava. The specific specimen appears to be a stream-tumbled or weathered pebble from a sedimentary or alluvial deposit. The orange staining comes from iron oxide (hematite or limonite) infiltration into cracks.

Uses & Applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as semi-precious gemstones in jewelry.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is known as rock crystal, but iron impurities commonly give it various colors including the orange/yellow tones seen here.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass and steel), lack of cleavage, and translucent appearance. It is found globally in almost all geological environments.

Identified on: 4/28/2026

Mode: Standard