igneous
Weathered quartz-bearing rock, possibly rhyolite or granite
Indeterminate felsic igneous rock; likely quartz–feldspar aggregate with iron-oxide staining
AI-generated identification · may be incorrectLight gray to pink-beige, dull to slightly glassy, fine- to medium-grained, with visible pale crystals and brown oxidation. Estimated hardness 6–7 Mohs; cleavage is not apparent and specific gravity is roughly 2.6–2.7.
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Physical properties
Light gray to pink-beige, dull to slightly glassy, fine- to medium-grained, with visible pale crystals and brown oxidation. Estimated hardness 6–7 Mohs; cleavage is not apparent and specific gravity is roughly 2.6–2.7.
Formation & geological history
Probably crystallized from silica-rich magma as granite or an erupted equivalent such as rhyolite, then weathered and surface-stained by iron oxides. An exact geological age and identification require a clearer view or testing.
Uses & applications
Ordinary material has little commercial value as a small specimen; related rocks are used for aggregate, building stone, countertops, and decorative landscaping.
Geological facts
The reddish-brown patches likely represent limonite or hematite formed during weathering. Quartz-bearing rocks commonly resist erosion and remain as rounded pebbles.
Field identification & locations
Look for quartz’s glassy fracture, feldspar’s blocky cleavage, and a granular texture; a steel nail should not scratch it, though a knife may scratch softer weathered areas. Common in continental crust and stream gravels worldwide.
