sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Hardness: 6.5-7 on Mohs scale. Color: Mustard yellow to golden brown. Luster: Vitreous to waxy. Crystal Structure: Trigonal (microcrystalline/cryptocrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58-2.91.

Hardness: 6
Color: Mustard yellow to golden brown
Luster: Vitreous to waxy

Identified June 10, 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 primarily in sedimentary environments when silica-rich fluids permeate through volcanic ash or other porous materials, gradually replacing organic material or filling cavities. The yellow color is caused by the presence of Goethite or other iron oxides.

Uses & applications

Used extensively as a gemstone for jewelry (cabochons, beads), decorative carvings, lapidary arts, and as a collector's specimen. In industry, it was historically used for flintknapping tools due to its conchoidal fracture.

Geological facts

Yellow jasper has been used throughout history as a stone of protection and discernment. It is a variety of chalcedony and is often found as smooth river stones due to its durability against erosion.

Field identification & locations

Identify in the field by its opaque appearance, waxy luster, and lack of cleavage (smooth, curved break surfaces). It is common in the Pacific Northwest of the USA, Africa, and Brazil. Collectors should look for patterns like dendritic inclusions or orbicular structures.

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