metamorphic
Likely tumbled jasper or iron-stained quartzite
Microcrystalline quartz (SiO₂), possibly quartzite with iron-oxide inclusions
AI-generated identification · may be incorrectBrown-red and gray mottling, opaque, waxy to dull luster, and irregularly rounded from tumbling; quartz hardness is about 7 Mohs, with no obvious cleavage and specific gravity near 2.6. The dark top may be iron/manganese staining or a cavity rather than a crystal.
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Physical properties
Brown-red and gray mottling, opaque, waxy to dull luster, and irregularly rounded from tumbling; quartz hardness is about 7 Mohs, with no obvious cleavage and specific gravity near 2.6. The dark top may be iron/manganese staining or a cavity rather than a crystal.
Formation & geological history
Likely formed from silica-rich sediment or volcanic material later altered and cemented, with red coloration caused by hematite or goethite; exact geological age cannot be determined from the photograph. Tumbled finishing is human processing, but the material remains geological.
Uses & applications
Used as a low-cost lapidary stone for tumbling, cabochons, ornaments, and crafts; similar jasper and quartzite are also used decoratively and occasionally as aggregate.
Geological facts
Jasper is an opaque variety of chalcedony, while quartzite is recrystallized sandstone; both can show nearly identical patterns in small polished pieces.
Field identification & locations
Test hardness against glass or a steel file, inspect for quartz-like granular fracture, and avoid relying on color alone; common sources include Brazil, India, Madagascar, and the western United States. Identification is provisional because the image is small and the specimen appears partly rough.
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