sedimentary

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and clay impurities

Hardness: 6.5-7 (Mohs scale); Color: Tan, brown, ochre, sienna, and blue-grey; Luster: Dull/waxy when raw, vitreous when polished; Crystal Structure: Microcrystalline (Trigonal); Cleavage: None (Conchoidal fracture)

Hardness: 6
Color: Tan, brown, ochre, sienna, and blue-grey
Luster: Dull/waxy when raw, vitreous when polished

Identified April 21, 2026More sedimentary →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed from the petrification of mud and clay in volcanic ash flows. As water seeped through the ash, it picked up minerals like iron and manganese, redepositing them as silica-rich mud that eventually hardened into microcrystalline quartz.

Uses & applications

Used primarily in lapidary arts for making cabochons, beads, jewelry, and ornamental carvings. It is also popular as a pocket stone for collectors.

Geological facts

It is often called 'Nature's painting' because the patterns can resemble landscape scenery, such as mountains, deserts, and rivers. This specific piece is likely a river-tumbled specimen based on its smooth, rounded edges.

Field identification & locations

Identify by its opaque, multi-colored banded or scenic patterns. It is very hard and cannot be scratched by a steel knife. Common in the Pacific Northwest region of the USA (Idaho and Oregon).

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Sandstone

Arenite (primarily SiO2)

sedimentary

Chert Breccia

Brecciated Chert (Microcrystalline Silica)

sedimentary

Sandstone Grain

Clastic Sedimentary Rock Grain (SiO2 dominated)

sedimentary

Shale or Slaty Mudstone

Argillaceous sedimentary rock

sedimentary

Sandstone

Arenite

sedimentary