mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan/yellow (due to iron oxide staining); Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to tan/yellow (due to iron oxide staining)
Luster: Vitreous to waxy

Identified June 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous and metamorphic rocks. This specific specimen appears to be a water-worn river pebble, shaped by erosion and stained by groundwater minerals over thousands of years.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative stone or landscaping gravel.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Iron-stained quartz like this is often referred to as 'yellow quartz' or, if the color is deep enough, it may be associated with citrine-like coloration.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. It is found globally in riverbeds, beaches, and mountain soil. Collectors look for clarity or unique weathering patterns.