sedimentary

Iron-rich chert or jasper pebble

Microcrystalline quartz (SiO₂), likely stained by iron oxides

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7, reddish-brown to gray-brown, with a dull to waxy luster and very fine-grained structure; no visible cleavage and conchoidal fracture. The granular pale patches may indicate weathering or minor quartz/quartzite inclusions.

Identified August 30, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed from silica-rich sediment that recrystallized into microcrystalline quartz, then acquired its brown-red color from hematite or limonite. Chert and jasper commonly form in marine sedimentary environments, generally from Precambrian through Cenozoic ages.

Uses & applications

Used as an ornamental stone, lapidary material, tumbled stone, and historically for sharp tools; this small rough specimen has primarily educational or decorative value.

Geological facts

Jasper is an opaque, iron-stained variety of chalcedony, while chert is the broader fine-grained silica category. A steel file should barely scratch it, whereas glass can be scratched by a fresh edge.

Field identification & locations

Common in gravel beds, river channels, exposed sedimentary formations, and glacial deposits worldwide. Identification would be improved by a fresh fracture, streak test, hardness test, and examination for a waxy texture; exact locality is needed for a precise name.