metamorphic
Weathered quartz-bearing metamorphic rock, likely mica schist or gneiss
Quartz–feldspar–mica schist/gneiss; exact identification is limited by the blurred image
AI-generated identification · may be incorrectGray to brown, fine- to medium-grained, dull to weakly sparkling luster, with possible foliation and rusty iron-oxide staining. Typical hardness is about 6–7 for quartz/feldspar, with mica cleavage; density is roughly 2.6–2.8 g/cm³.
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Physical properties
Gray to brown, fine- to medium-grained, dull to weakly sparkling luster, with possible foliation and rusty iron-oxide staining. Typical hardness is about 6–7 for quartz/feldspar, with mica cleavage; density is roughly 2.6–2.8 g/cm³.
Formation & geological history
Formed when shale or another quartz-rich sediment was buried, heated, and compressed during mountain building; foliation developed from aligned mica minerals. The specimen’s precise geological age and metamorphic grade cannot be determined visually.
Uses & applications
Used locally as crushed aggregate, fill, or decorative stone; attractive foliated pieces may be collected, but this small weathered fragment has little commercial value.
Geological facts
The brown patches are likely limonite/goethite produced by weathering of iron-bearing minerals. A fresh broken surface and a hand lens would better distinguish schist from gneiss or weathered granite.
Field identification & locations
Common in metamorphic belts worldwide, including the Appalachian, Rocky, and European mountain regions. Look for planar foliation, quartz grains, mica flakes, and resistance to a steel knife; fizzing with dilute acid would indicate carbonate instead.
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