sedimentary

Yellow Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs), Color: Mustard yellow to brownish-yellow, Luster: Vitreous to greasy, Crystal Structure: Hexagonal/Trigonal (microcrystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.58-2.91

Hardness: 6

Identified February 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when silica-rich fluids permeate through volcanic ash or sedimentary beds; the yellow color is caused by the inclusion of iron oxide (goethite). It is often found as water-worn river pebbles.

Uses & applications

Primary use in ornamental jewelry, lapidary cabochons, and decorative items. Historically used for making stone tools due to its sharp conchoidal fracture.

Geological facts

Yellow Jasper is often called a 'nurturing stone' in metaphysical circles. In geological terms, it is an opaque form of chalcedony. The smooth exterior of this specimen indicates it has been tumbled by water in a river or creek bed over a long period.

Field identification & locations

Identify by its smooth, waxy surface and its ability to scratch glass. Look for it in riverbeds, glacial till, or coastal areas. Collectors should check for high-contrast patterns or 'brecciation' which increases value.