sedimentary

Yellow Jasper

Silicon Dioxide (SiO2 with iron oxide inclusions)

AI-generated identification · may be incorrect

Hardness of 6.5-7 on the Mohs scale, opaque mustard to brownish-yellow color, waxy to dull luster, microcrystalline/cryptocrystalline trigonal structure, smooth conchoidal fracture with no cleavage.

Identified July 28, 2026More sedimentary →

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Physical properties

Hardness of 6.5-7 on the Mohs scale, opaque mustard to brownish-yellow color, waxy to dull luster, microcrystalline/cryptocrystalline trigonal structure, smooth conchoidal fracture with no cleavage.

Formation & geological history

Formed when fine microcrystalline quartz precipitates from silica-rich waters, incorporating iron oxide minerals (goethite or hematite) that impart the characteristic yellow color. Found in sedimentary environments and alluvial deposits.

Uses & applications

Popular for lapidary work, cabochons, tumbled decorative stones, jewelry, carving, and rock collections.

Geological facts

Jasper has been used since antiquity for seals, ornaments, and amulets. Yellow jasper specifically gets its vibrant color from hydrated iron oxides trapped inside the quartz matrix.

Field identification & locations

Can be identified in the field by its distinct mustard-yellow opaque hue, smooth conchoidal fracturing, and high hardness (scratches glass easily). Common in regions with ancient sedimentary rocks and riverbeds across Brazil, South Africa, Madagascar, and the Western United States.