mineral

Quartz (Milky or Iron-Stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: White to yellowish-tan due to iron oxide staining. Luster: Vitreous (glassy) to greasy. Crystal structure: Hexagonal/Trigonal. Cleavage: Indistinct/Conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: White to yellowish-tan due to iron oxide staining
Luster: Vitreous (glassy) to greasy

Identified March 8, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins, pegmatites, and as a primary mineral in igneous rocks like granite. This specimen likely originated from a quartz vein where water rich in silica and iron minerals deposited the material over millions of years.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), abrasives, and as a gemstone when high quality. Common specimens are used as garden stones or landscape aggregate.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz like this is often found near gold deposits, earning it the nickname 'gold-bearing quartz' in certain mining regions.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife and its lack of clear cleavage planes. Commonly found in riverbeds, mountains, and desert pavements worldwide. Look for the irregular, shell-like (conchoidal) fracture surfaces.

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