metamorphic
Iron-stained quartz-rich rock
Likely quartzite with hematite/goethite staining; exact identification requires testing
AI-generated identification · may be incorrectMostly pale gray, translucent-to-white quartz with rusty red-brown iron-oxide patches and a granular texture. Quartz hardness is 7 Mohs, vitreous luster, and no cleavage; the rock’s texture and strength vary with cementation and metamorphism.
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Physical properties
Mostly pale gray, translucent-to-white quartz with rusty red-brown iron-oxide patches and a granular texture. Quartz hardness is 7 Mohs, vitreous luster, and no cleavage; the rock’s texture and strength vary with cementation and metamorphism.
Formation & geological history
Likely formed when quartz-rich sandstone was recrystallized under heat and pressure, with later iron-bearing fluids or weathering producing the red staining. Its age and precise formation environment cannot be determined from appearance alone.
Uses & applications
Quartzite is used as building and decorative stone, aggregate, and occasionally as a lapidary material; this specimen is primarily suitable for collecting or display.
Geological facts
Red coloration commonly comes from hematite or goethite coatings between quartz grains rather than from red quartz crystals.
Field identification & locations
Look for interlocking quartz grains and a hard surface that resists scratching by steel; iron staining alone is not diagnostic, and a fresh broken surface can help distinguish quartzite from sandstone. Quartzite occurs worldwide in metamorphic belts.
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