igneous
Iron-stained quartz-rich rock, likely granite or pegmatite fragment
Weathered granite/pegmatite; mainly quartz (SiO₂) with feldspar and iron-oxide staining
AI-generated identification · may be incorrectCoarse, uneven crystalline texture; pale gray to pink/orange, with vitreous quartz and dull feldspar. Quartz hardness ~7; feldspar ~6; no obvious cleavage visible; bulk specific gravity roughly 2.6–2.7.
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Physical properties
Coarse, uneven crystalline texture; pale gray to pink/orange, with vitreous quartz and dull feldspar. Quartz hardness ~7; feldspar ~6; no obvious cleavage visible; bulk specific gravity roughly 2.6–2.7.
Formation & geological history
Likely crystallized slowly from silica-rich magma, producing interlocking quartz and feldspar grains; orange-brown colors result from weathering and oxidation of iron-bearing minerals. Precise age cannot be determined visually; rocks near 46.7°N, 92.0°W commonly include Precambrian granitic and metamorphic rocks, making this regionally plausible.
Uses & applications
Common granite is used as crushed stone, aggregate, building stone, and monuments; small unattractive fragments generally have negligible commercial value.
Geological facts
The specimen appears natural rather than glass, ceramic, or concrete. Its rusty surface is probably limonite/goethite coating or alteration.
Field identification & locations
Look for visible interlocking quartz and feldspar grains, pink feldspar, and a hard surface that scratches glass. A hand lens and streak, acid, or hardness tests would improve identification; it could also be a weathered gneiss or arkosic rock if layering is present.
