mineral

Tumbled yellow jasper or chert

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

AI-generated identification · may be incorrect

Typically hardness 6.5–7 Mohs, opaque yellow to tan, with a dull-to-waxy luster and no visible cleavage; compact microcrystalline quartz has a fine, uniform texture. The rounded shape suggests natural abrasion or tumbling, though the image alone cannot confirm composition.

Identified August 24, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater replaces or fills sedimentary material, with iron oxides producing yellow coloration; chert and jasper commonly formed in sedimentary environments from Precambrian to recent ages. Exact age and locality are not determinable from the photograph.

Uses & applications

Used as ornamental stone, beads, cabochons, carvings, and lapidary material; tougher pieces may serve as minor aggregate or decorative landscaping stone.

Geological facts

Jasper is an opaque variety of chalcedony, while chert is a broader term for microcrystalline quartz; the boundary between them is often informal and color-based.

Field identification & locations

Look for glassy or waxy fracture, inability to scratch with a steel knife, and a white streak; quartz-rich material scratches ordinary glass. Common worldwide, especially in sedimentary terrains and volcanic regions.