mineral

Quartz (Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Mohs hardness of 7, vitreous to greasy luster, trigonal crystal system, white to milky appearance with brownish-orange iron oxide staining, shell-like (conchoidal) fracture, and lack of cleavage.

Identified July 24, 2026More mineral →

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Physical properties

Mohs hardness of 7, vitreous to greasy luster, trigonal crystal system, white to milky appearance with brownish-orange iron oxide staining, shell-like (conchoidal) fracture, and lack of cleavage.

Formation & geological history

Forms in hydrothermal veins, pegmatites, and igneous intrusions as silica-rich fluids cool and crystallize under varied temperature and pressure conditions.

Uses & applications

Widely used in electronics, optics, glassmaking, abrasives, construction aggregates, and popular among amateur rock collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron oxide staining often gives otherwise clear or white quartz a distinct orange, red, or yellowish coat along cracks and surfaces.

Field identification & locations

Identified in the field by its high hardness (scratches glass), conchoidal fracture, and resistance to chemical weathering. Commonly found in stream beds, granite outcrops, and gravel deposits worldwide.