mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Clear to yellowish/tan due to iron oxide staining, Luster: Vitreous (glassy) to greasy, Structure: Hexagonal/Trigonal, Grainy texture, No cleavage.

Identified June 27, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 (Mohs scale), Color: Clear to yellowish/tan due to iron oxide staining, Luster: Vitreous (glassy) to greasy, Structure: Hexagonal/Trigonal, Grainy texture, No cleavage.

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments. This specific specimen appears to be a weathered water-worn fragment from a hydrothermal vein or pegmatite that has been exposed to iron-rich fluids.

Uses & applications

Industrial use in glassmaking, electronics (piezoelectric properties), abrasives, and as a popular collector specimen for beginners.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz is often mistaken for citrine, but the yellow coloring is usually just a surface coating or infusion in cracks rather than a change in the crystal lattice.

Field identification & locations

Identify by its 7 hardness (scratches glass but isn't scratched by steel) and conchoidal (shell-like) fracture. Found globally in riverbeds, mountains, and beaches.