sedimentary

Yellow Jasper

Silicon Dioxide with Iron inclusions (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Mustard yellow to golden brown; Luster: Vitreous to greasy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

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

Identified April 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of fine silica and volcanic ash in sedimentary environments. Its yellow color comes from high concentrations of goethite or clay inclusions. It can form in various geological ages wherever silica-rich fluids permeate porous rock.

Uses & applications

Primarily used for lapidary work, cabochons, beads, and metaphysical specimens. Historically used for making tools due to its conchoidal fracture which creates sharp edges.

Geological facts

Jasper is an opaque variety of chalcedony. In ancient times, yellow jasper was often associated with protection during travel and the element of earth. It is a stone that holds a polish very well due to its dense structure.

Field identification & locations

Identify by its opacity (it will not let light through even at thin edges, unlike agate), smooth waxy feel, and ability to scratch glass. Commonly found in riverbeds, mountains, and desert regions globally.

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