igneous
Tumbled quartz-rich feldspathic rock, possibly granite or granitic gneiss
Quartz–feldspar aggregate; likely granitoid (quartz + feldspar ± mica and iron-oxide staining)
AI-generated identification · may be incorrectHardness about 6–7 Mohs; pale gray-white with brown/red iron staining and dark mineral flecks, displaying a mostly dull to vitreous luster. The irregular granular texture suggests interlocking quartz and feldspar rather than visible crystal faces or cleavage.
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Physical properties
Hardness about 6–7 Mohs; pale gray-white with brown/red iron staining and dark mineral flecks, displaying a mostly dull to vitreous luster. The irregular granular texture suggests interlocking quartz and feldspar rather than visible crystal faces or cleavage.
Formation & geological history
Likely crystallized slowly from silica-rich magma deep in the crust, potentially Precambrian to younger, then weathered and naturally or artificially tumbled. Exact age and rock name require a fresh surface or microscopic examination.
Uses & applications
Common as landscaping stone, aggregate, lapidary material, and inexpensive polished decorative stone; generally low jewelry value unless unusually attractive or locally significant.
Geological facts
Quartz remains glass-scratching hard, while feldspar commonly shows cleavage and is slightly softer. The reddish-brown patches are probably iron oxides produced by weathering of iron-bearing minerals.
Field identification & locations
Common in continental crust and river gravels worldwide; likely sources include granitic terrains in North America, Europe, India, Brazil, and Australia. A streak test, hardness test, and close inspection for feldspar cleavage can help distinguish it from quartzite or weathered gneiss.
