mineral

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Clear to white with yellow/brown iron staining
Luster: Vitreous (glassy) to greasy

Identified April 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal activity or the cooling of silica-rich magma/lava. It is ubiquitous throughout geological time, appearing in almost all rock-forming environments including metamorphic and sedimentary processes.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a common gemstone or landscaping material.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The yellow staining in this specimen is likely due to 'limonite' or iron oxide coatings accumulated from weathering.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel) and lack of cleavage. It is commonly found in riverbeds, mountains, and as veins in other rocks globally.