metamorphic
Tumbled quartz-rich stone, likely quartzite
Quartzite (mostly crystalline SiO₂), possibly quartz/chalcedony
AI-generated identification · may be incorrectHardness about 7 Mohs; creamy white to pale pink with cloudy, granular texture and a vitreous-to-waxy luster. Massive, nonfoliated structure with no obvious cleavage; specific gravity approximately 2.65.
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Physical properties
Hardness about 7 Mohs; creamy white to pale pink with cloudy, granular texture and a vitreous-to-waxy luster. Massive, nonfoliated structure with no obvious cleavage; specific gravity approximately 2.65.
Formation & geological history
Quartzite forms when quartz-rich sandstone is recrystallized under heat and pressure during metamorphism, commonly during mountain-building events. The specimen appears tumbled and polished, so its exact geological age and identity cannot be determined from the image.
Uses & applications
Used as crushed stone, aggregate, building and decorative stone; attractive pieces may be sold as lapidary or worry stones. It is generally inexpensive unless unusually patterned or gem-quality.
Geological facts
Quartzite commonly breaks across quartz grains rather than around them and is typically harder than ordinary sandstone. Pink tones may reflect iron staining or minor feldspar impurities.
Field identification & locations
Look for a uniformly hard, quartz-rich surface that scratches glass and shows no acid reaction; sandstone-like layering may be absent after metamorphism. Common worldwide, including Brazil, India, the United States, and Scandinavia.
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