mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white with orange/brown iron staining and greenish inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Luster: Vitreous to waxy

Identified June 22, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in a wide variety of environments, most commonly from the cooling of magma or by hydrothermal precipitation. Iron staining occurs when the mineral is exposed to oxygen and water in the presence of iron-rich sediments.

Uses & applications

Industrial uses include glass making, abrasives, and electronics. Small stained specimens are primarily of interest to hobbyist collectors or used as tumble stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz is often mistaken for carnelian or citrine by beginner collectors.

Field identification & locations

Identified in the field by its hardness (it will scratch glass), lack of cleavage, and resistance to weathering. Commonly found in stream beds, mountain trails, and as veins in larger rock formations.