mineral
Tumbled yellow jasper (likely yellow calcite or serpentine)
Microcrystalline quartz, SiO₂, if jasper; appearance may also fit calcite, CaCO₃, or serpentine-group minerals
AI-generated identification · may be incorrectSmooth, rounded, opaque yellow-brown specimen with a waxy to dull luster; likely Mohs 3–7 depending on composition. No visible crystals or cleavage; photography alone cannot distinguish the alternatives reliably.
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Physical properties
Smooth, rounded, opaque yellow-brown specimen with a waxy to dull luster; likely Mohs 3–7 depending on composition. No visible crystals or cleavage; photography alone cannot distinguish the alternatives reliably.
Formation & geological history
Yellow jasper forms when silica-rich fluids replace or cement iron-bearing sediments or volcanic material; calcite and serpentine have different origins. These materials range from ancient Precambrian to much younger geological deposits.
Uses & applications
Used as a decorative and lapidary stone in cabochons, carvings, polished stones, and jewelry; not generally important for construction in this form.
Geological facts
The color commonly comes from iron oxides or hydroxides. A steel scratch test and dilute hydrochloric-acid test can separate likely jasper from calcite, though testing may mark the specimen.
Field identification & locations
Commonly found as water-worn pebbles or in hydrothermal and volcanic terrains worldwide; yellow jasper is widespread in India, Madagascar, Brazil, Australia, and the western United States. If it scratches glass, jasper is more likely; fizzing in acid indicates calcite.
