mineral
Likely weathered quartz-bearing rock fragment
Indeterminate; appears to contain quartz (SiO₂) with iron-oxide staining, possibly from quartzite, granite, or pegmatite
AI-generated identification · may be incorrectSmall angular specimen with translucent to whitish-gray and rusty-brown areas, vitreous-to-dull luster, and irregular fracture. Quartz has Mohs hardness 7, no cleavage, and specific gravity about 2.65; the exact rock cannot be determined reliably from this image.
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Physical properties
Small angular specimen with translucent to whitish-gray and rusty-brown areas, vitreous-to-dull luster, and irregular fracture. Quartz has Mohs hardness 7, no cleavage, and specific gravity about 2.65; the exact rock cannot be determined reliably from this image.
Formation & geological history
Likely a naturally weathered fragment eroded from a quartz-rich igneous or metamorphic outcrop and transported in stream gravel; its geological age is unknown.
Uses & applications
Unlikely to have industrial or jewelry value at this size; quartz-rich material is used in glass, ceramics, electronics, and aggregate when present in bulk.
Geological facts
Brown coloration commonly results from oxidation of iron-bearing minerals, producing hematite or goethite coatings. The specimen may show several minerals rather than being a single crystal.
Field identification & locations
Test whether it scratches glass but not a steel blade, and inspect a fresh break for glassy quartz; acid testing and a magnifier may reveal carbonate or mica. Quartz-rich stream gravels are widespread worldwide.
