metamorphic
Weathered quartz-rich rock, likely quartzite or milky-quartz vein material
Quartzite (dominantly SiO₂), possibly quartz-vein breccia with iron-oxide staining
AI-generated identification · may be incorrectMostly white to gray, massive and sugary-to-waxy quartz with dark gray bands and weathered cavities; quartz hardness is Mohs 7, vitreous to dull luster, no cleavage, and conchoidal fracture. The rounded surface appears strongly weathered and may include darker matrix minerals or iron/manganese oxides.
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Physical properties
Mostly white to gray, massive and sugary-to-waxy quartz with dark gray bands and weathered cavities; quartz hardness is Mohs 7, vitreous to dull luster, no cleavage, and conchoidal fracture. The rounded surface appears strongly weathered and may include darker matrix minerals or iron/manganese oxides.
Formation & geological history
Likely formed when quartz-rich sandstone recrystallized during metamorphism, or when silica-bearing fluids filled fractures and later became brecciated; exact age cannot be determined from the image. Such rocks commonly occur in metamorphic belts and exposed quartz veins.
Uses & applications
Quartzite is used as crushed stone, aggregate, road material, and dimension stone; attractive pieces may be collected or polished, though this specimen appears ordinary rather than gem quality.
Geological facts
The white areas should resist scratching by a steel knife, while the dark matrix may scratch more easily. Acid generally produces no reaction unless carbonate minerals are present in the cavities or matrix.
Field identification & locations
Common in mountain terrains, glacial deposits, and stream gravels. Field identification relies on extreme hardness, abundant quartz, lack of cleavage, and a granular texture; a thin section or hardness test would distinguish quartzite from massive vein quartz.
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