mineral

Tumbled yellow-brown jasper or chalcedony

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

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; mustard-yellow to brown, opaque to slightly translucent, with a waxy to vitreous luster and no visible cleavage. The rounded shape indicates tumbling or natural water abrasion; specific gravity is about 2.6.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids fill cavities or replace rock, with iron oxides producing the yellow-brown coloration; commonly Cenozoic to older, depending on its host deposit. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used as a lapidary stone for cabochons, beads, carvings, and decorative objects; attractive pieces are collectible but generally inexpensive.

Geological facts

Jasper is an opaque variety of chalcedony, while more translucent material is usually called chalcedony or carnelian. The specimen may also be yellow agate if internal banding is present but obscured by its finish.

Field identification & locations

Look for quartz-like hardness, a smooth waxy surface, absence of cleavage, and inability to scratch it with a steel blade; it should scratch ordinary glass. Common sources include Brazil, Madagascar, India, Mexico, and the western United States.