mineral

Tumbled yellow jasper (probable)

Jasper, an opaque microcrystalline variety of quartz; chiefly SiO₂ with iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; mustard-yellow to brown mottling, opaque, waxy to vitreous luster, cryptocrystalline quartz with no obvious cleavage, and specific gravity near 2.6. The smooth rounded surface indicates tumbling and polishing.

Identified September 12, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement volcanic or sedimentary material, with iron oxides producing the yellow coloration. Deposits are generally ancient, though the specimen’s geological age cannot be determined visually.

Uses & applications

Used for cabochons, beads, carvings, ornamental objects, and inexpensive lapidary pieces; it has little industrial value compared with ordinary quartz.

Geological facts

Jasper is technically a rock rather than a single mineral, and color patterns often reflect trace iron, clay, and relic textures from the host rock.

Field identification & locations

Identify it by its opaque yellow color, mottled patterns, glassy/waxy polish, lack of cleavage, and ability to scratch ordinary glass. Common sources include India, Madagascar, Brazil, Australia, and the western United States.