sedimentary

Yellow Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs), Color: mustard yellow to ochre, Luster: vitreous to waxy, Crystal Structure: Trigonal (Microcrystalline), Cleavage: None, Fracture: conchoidal.

Hardness: 6

Identified June 2, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs), Color: mustard yellow to ochre, Luster: vitreous to waxy, Crystal Structure: Trigonal (Microcrystalline), Cleavage: None, Fracture: conchoidal.

Formation & geological history

Formed through the accumulation of fine silica-rich volcanic ash or sedimentary debris, where silica is replaced by fibrous quartz crystals. These can date back millions of years in various sedimentary environments.

Uses & applications

Commonly used for lapidary work, jewelry (cabs or beads), decorative carving, and as a popular specimen for rock collection and metaphysical uses.

Geological facts

Yellow jasper is a variety of chalcedony. Its yellow color is primarily caused by impurities of iron oxides (goethite/limonite). Historically, it has been used as a grounding stone and to help with self-discipline.

Field identification & locations

Identify by its solid mustard yellow color, lack of transparency (it is opaque), and its smooth, conchoidal (shell-like) fracture. Found worldwide, with significant deposits in India, Russia, and the USA (Oregon and Idaho).