metamorphic
Blue quartzite (likely)
Quartzite, composed predominantly of quartz (SiO₂); blue coloration may come from fine mineral inclusions
AI-generated identification · may be incorrectA rounded, polished blue-gray stone with a pale streak and cloudy patches. Quartz is Mohs 7, vitreous to dull, and has no cleavage; the image does not show enough detail to confirm its texture or exact mineral content.
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Physical properties
A rounded, polished blue-gray stone with a pale streak and cloudy patches. Quartz is Mohs 7, vitreous to dull, and has no cleavage; the image does not show enough detail to confirm its texture or exact mineral content.
Formation & geological history
Quartzite forms when quartz-rich sandstone is recrystallized by heat and pressure. Its age and the cause of this specimen’s blue color cannot be determined from the photograph.
Uses & applications
Often used as a decorative or ornamental stone, in landscaping, and as a polished collectible; suitable uses depend on confirmed composition.
Geological facts
Blue stones sold as tumbled specimens may also be dyed quartzite or another blue mineral, so appearance alone cannot establish identity.
Field identification & locations
The smooth rounded shape suggests tumbling or water wear. The reported location in Sergipe, Brazil, is not enough to confirm a local source; check for dye in cracks and use hardness or mineral tests for identification.
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