sedimentary / mineral
Jasper / Chert (polished)
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness 6.5-7, brown/tan color, waxy to vitreous luster when polished, opaque, conchoidal fracture.
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Physical properties
Hardness 6.5-7, brown/tan color, waxy to vitreous luster when polished, opaque, conchoidal fracture.
Formation & geological history
Formed as a silica precipitate in sedimentary environments, often replacing original materials like wood or forming nodules in limestone.
Uses & applications
Commonly used as a decorative stone, tumbled stone, or in inexpensive jewelry.
Geological facts
Jasper is an opaque variety of chalcedony, usually brown, yellow, or reddish due to iron inclusions. This piece has been tumbled or polished to a smooth finish.
Field identification & locations
Identified by its hardness (scratches glass), opacity, and smooth polished surface in this form. Often found in riverbeds or as nodules.
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