mineral

Iron-stained quartz or quartz-rich fragment

Quartz (SiO₂), possibly with limonite/goethite staining

AI-generated identification · may be incorrect

Hardness about 7 Mohs; white to cream, opaque to translucent, with a vitreous to dull luster and irregular fracture. Crystalline quartz is trigonal, though crystal faces are poorly developed here; cleavage is absent and specific gravity is about 2.65.

Identified September 6, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed in a hydrothermal vein or weathered quartz-bearing rock, with iron oxides producing the brown-yellow staining. Its geological age cannot be determined from the photograph.

Uses & applications

Quartz is used in glass, ceramics, electronics, abrasives, and construction aggregate; attractive pieces may be collected, but this specimen appears ordinary rather than gem quality.

Geological facts

The rough, granular appearance and cream color are consistent with quartz, but calcite or feldspar cannot be excluded without testing. A steel file should not scratch quartz; dilute vinegar or hydrochloric acid would fizz on calcite.

Field identification & locations

Common in quartz veins, pegmatites, granites, metamorphic rocks, and stream gravels worldwide. Check for glassy fracture, translucency, and hardness; acid testing and a streak test help distinguish alternatives.