metamorphic
Iron-stained quartz-rich rock, possibly ferruginous quartzite
Quartz-rich ferruginous rock; exact identification is uncertain from the photograph
AI-generated identification · may be incorrectOpaque, rough, reddish-brown specimen with pale quartz-like patches and a granular to mottled texture. If quartzite, it is mainly quartz (Mohs hardness 7), with iron oxides producing the color; luster is dull to locally vitreous and cleavage is absent.
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Physical properties
Opaque, rough, reddish-brown specimen with pale quartz-like patches and a granular to mottled texture. If quartzite, it is mainly quartz (Mohs hardness 7), with iron oxides producing the color; luster is dull to locally vitreous and cleavage is absent.
Formation & geological history
Could have formed when quartz-rich sandstone was metamorphosed and stained or cemented by iron oxides. The image alone cannot establish its age or distinguish quartzite from iron-rich vein material or another weathered rock.
Uses & applications
Commonly used as decorative or landscaping stone; attractive pieces may be collected, but this specimen does not show gem-quality features.
Geological facts
Red and brown hues commonly come from hematite or goethite. A scratch test and examination of a fresh broken surface would help confirm whether quartz dominates.
Field identification & locations
Look for hard, interlocking quartz grains and resistance to scratching by a steel knife; iron staining may leave reddish-brown streaks. Quartzite occurs worldwide, especially in ancient mountain belts and exposed sandstone formations.
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