mineral

Tumbled yellow jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; opaque mustard-yellow body, smooth tumbled surface, waxy to dull luster, cryptocrystalline structure, and no visible cleavage. The rounded shape is human-processed rather than natural.

Identified September 19, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids fill fractures or cavities and later become chalcedony or jasper; yellow coloration generally comes from hydrated iron oxides. Deposits occur in many geological ages and volcanic or sedimentary settings.

Uses & applications

Used for beads, cabochons, carvings, decorative objects, and lapidary collections; it has little industrial value as a small polished piece.

Geological facts

Jasper is an opaque variety of chalcedony, unlike translucent agate. The specimen could also be yellow aventurine or serpentine, but its appearance most strongly suggests tumbled yellow jasper.

Field identification & locations

Commonly found as colorful river pebbles or lapidary rough, especially from volcanic terrains. It should resist scratching by a steel knife and not react with dilute acid; confirmatory identification requires testing hardness and specific gravity.