mineral

Tumbled brown agate or jasper

Microcrystalline quartz (chalcedony), SiO₂, likely iron-oxide-bearing

AI-generated identification · may be incorrect

Polished, rounded pebble with tan, brown, reddish, and gray areas; waxy to vitreous luster and no visible cleavage. Mohs hardness is approximately 6.5–7; cryptocrystalline quartz has a fine fibrous structure and specific gravity near 2.6.

Identified August 23, 2026More mineral →

Explore Tumbled brown agate or jasper 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

Likely formed when silica-rich groundwater filled cavities or fractures in volcanic rock, with iron oxides producing the brown-red coloration; age depends on source deposit, commonly Paleozoic to Cenozoic.

Uses & applications

Used for cabochons, beads, tumbling, ornaments, and small decorative objects; attractive pieces have modest lapidary value.

Geological facts

The specimen appears tumbled and polished, so natural crystal faces and field texture are absent; its exact identification cannot be confirmed from the photograph alone.

Field identification & locations

Commonly found in volcanic terrains and gravel deposits worldwide. Agate often shows banding or translucent edges, whereas jasper is more opaque and uniformly colored; a quartz hardness test and strong light transmission help distinguish them.