mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Tan to brown (due to iron oxide staining), naturally clear to white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: Poor/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Luster: Vitreous to greasy

Identified June 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous pegmatites. This specific specimen shows external iron-oxide staining common in surface-level weathering environments.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), construction aggregates, and as gemstones or collector specimens.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is known as rock crystal, while impurities create varieties like amethyst, citrine, and smoky quartz.

Field identification & locations

Identify in the field by its hardness (will scratch glass), conchoidal (shell-like) fracture, and lack of reaction to acid. Commonly found in riverbeds, mountains, and desert pavement worldwide.