mineral

Tumbled jasper

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

AI-generated identification · may be incorrect

Opaque, rounded and polished; mottled reddish-brown, tan, and cream colors with earthy to waxy luster. Mohs hardness 6.5–7; cryptocrystalline quartz, no cleavage, specific gravity about 2.6.

Identified August 20, 2026More mineral →

Explore Tumbled jasper in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Opaque, rounded and polished; mottled reddish-brown, tan, and cream colors with earthy to waxy luster. Mohs hardness 6.5–7; cryptocrystalline quartz, no cleavage, specific gravity about 2.6.

Formation & geological history

Forms when silica-rich groundwater fills cavities or fractures and becomes colored by iron oxides during diagenesis or volcanic alteration. The specimen is likely geologically ancient, but its exact age and locality cannot be determined from the image.

Uses & applications

Used for tumbled stones, cabochons, carvings, beads, and ornamental objects; durable varieties are also used decoratively. Common material generally has modest value.

Geological facts

Jasper is an opaque variety of chalcedony rather than a distinct single mineral species; color patterns reflect impurities and replacement textures.

Field identification & locations

Common in volcanic and sedimentary terrains worldwide, including the western United States, Madagascar, Brazil, India, and Australia. Identification is supported by opacity, hardness, quartz-like heft, and resistance to scratching by steel; this polished pebble could also be iron-stained agate or another chert.