mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Tan to reddish-brown (surface staining), Luster: Vitreous to waxy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture)

Identified April 15, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Tan to reddish-brown (surface staining), Luster: Vitreous to waxy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture)

Formation & geological history

Commonly formed in hydrothermal veins or as a major constituent of igneous rocks like granite. This specific specimen appears to be a water-worn river pebble where iron oxide has stained its surface.

Uses & applications

Primarily used in glassmaking, electronics, and construction if in bulk; as a single pebble, it is a common pocket stone or educational specimen.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust. Pure quartz is clear, but impurities or surface oxidation create a wide spectrum of colors.

Field identification & locations

Identify by its hardness (scratches glass) and lack of cleavage. Found globally in riverbeds, beaches, and soil. Collectors look for clearer or more geometric crystals.