sedimentary

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque tan-orange color, waxy to dull luster, very fine-grained cryptocrystalline structure, and no visible cleavage. The smooth elongated shape indicates natural water wear or tumbling.

Identified August 26, 2026More sedimentary →

Explore Tumbled chert or jasper pebble in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Chert forms when silica-rich microfossil material or groundwater precipitates and lithifies, commonly within limestone or volcanic-associated sediments; jasper is an iron-rich opaque variety. Formation ages vary widely, from Paleozoic to recent, so the image cannot establish a specific age.

Uses & applications

Used as a durable aggregate, carving material, and lapidary stone; attractive jasper may be made into cabochons, beads, or polished specimens.

Geological facts

Its orange-brown color likely comes from iron oxides. Chert typically breaks with a curved, conchoidal fracture and can produce a sharp edge when freshly fractured.

Field identification & locations

Look for a glassy or waxy surface, uniform fine texture, and inability to scratch it with a steel knife; quartz should scratch glass. Common in stream gravels, glacial deposits, and sedimentary regions worldwide.