sedimentary

Tumbled jasper or iron-stained chert

Microcrystalline quartz (SiO₂), likely jasper/chert with iron-oxide staining

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; rounded, dull to waxy luster, opaque reddish-brown and gray coloration, with no visible cleavage and a cryptocrystalline quartz structure. The small size and smooth surface indicate natural or human tumbling.

Identified August 18, 2026More sedimentary →

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Physical properties

Formation & geological history

Jasper and chert form when silica-rich fluids replace or cement sediment, often incorporating iron oxides that produce red and brown colors. Formation ages vary widely, from Precambrian to much younger sedimentary environments.

Uses & applications

Commonly used for cabochons, beads, carvings, decorative stone, and inexpensive collectible specimens; it has little construction value in this form.

Geological facts

The specimen’s muted red-gray pattern is typical of iron-stained jasper, brecciated jasper, or chert, but the photograph cannot distinguish these confidently. A steel file or quartz scratch test can help assess its hardness, though testing may damage it.

Field identification & locations

Look for opaque color, a smooth waxy surface, conchoidal fracture, and resistance to scratching by steel. Common sources include river gravels and silica-rich sedimentary formations worldwide.