mineral

Yellow jasper or polished yellow chalcedony

Microcrystalline quartz, SiO₂, likely iron-stained jasper/chalcedony

AI-generated identification · may be incorrect

Opaque to slightly translucent mustard-yellow material with a smooth polish, waxy to vitreous luster, and no visible crystal faces. Quartz hardness is about 7 Mohs; specific gravity is approximately 2.6, with conchoidal fracture and no cleavage.

Identified August 10, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits microcrystalline quartz in cavities, veins, or sedimentary environments; yellow coloration commonly comes from iron oxides. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used as a cabochon, tumbled stone, carving material, and ornamental collectible; jasper is also used decoratively in small architectural objects.

Geological facts

The specimen’s rounded, polished form and opaque yellow color are consistent with yellow jasper, though resin, dyed chalcedony, or amber-like simulants cannot be excluded visually.

Field identification & locations

Field identification requires a hardness test, specific-gravity measurement, and examination for natural matrix or banding; quartz will scratch glass, while amber and resin will not. Yellow jasper occurs worldwide, notably in India, Madagascar, Brazil, and the western United States.