mineral
Tumbled yellow chalcedony or jasper pebble
Microcrystalline quartz (SiO₂), likely chalcedony with iron-oxide staining
AI-generated identification · may be incorrectPale yellow, opaque to slightly translucent, rounded and polished, with a waxy-to-dull luster; likely hardness 6.5–7 Mohs, no visible cleavage, and specific gravity about 2.6. The smooth surface indicates tumbling or natural water wear.
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Physical properties
Pale yellow, opaque to slightly translucent, rounded and polished, with a waxy-to-dull luster; likely hardness 6.5–7 Mohs, no visible cleavage, and specific gravity about 2.6. The smooth surface indicates tumbling or natural water wear.
Formation & geological history
Forms when silica-rich fluids fill cavities or fractures and precipitate microcrystalline quartz, with yellow coloration commonly caused by iron oxides or hydroxides. Exact age and locality cannot be determined from the photograph.
Uses & applications
Used as a low-cost lapidary stone, worry stone, cabochon, bead, or collector specimen; chalcedony and jasper are also used decoratively and occasionally in jewelry.
Geological facts
The specimen could also be yellow jasper, a closely related opaque quartz variety; distinguishing the two usually requires examining translucency, patterning, and sometimes testing composition.
Field identification & locations
Look for glassy or waxy luster, conchoidal fracture, absence of cleavage, and quartz-like hardness that can scratch steel or glass. Common sources include Brazil, Madagascar, India, Uruguay, and the western United States.
