sedimentary

Brown Jasper / River Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz

AI-generated identification · may be incorrect

Hardness: 6.5-7 on the Mohs scale. Color: Brownish-red to reddish-tan due to iron oxide inclusions. Luster: Vitreous to waxy when wet/polished. Structure: Microcrystalline aggregate. Cleavage: None, exhibits conchoidal fracture.

Hardness: 6
Color: Brownish-red to reddish-tan due to iron oxide inclusions
Luster: Vitreous to waxy when wet/polished

Identified July 23, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in sedimentary or low-grade metamorphic environments, often containing fine iron oxides. This pebble has been naturally rounded and smoothed by water abrasion in a stream, river, or coastal environment.

Uses & applications

Used in lapidary arts for tumbling, polishing, decorative landscape stones, and crafting cabochons for jewelry. Highly popular among amateur rock collectors and children.

Geological facts

Water-worn river pebbles gain their signature smooth, rounded shape after years of tumbling against other rocks and sand in flowing water. Jasper has been used since ancient times for carving seals and amulets.

Field identification & locations

Identified by its smooth, water-rounded shape, fine-grained opaque reddish-brown appearance, and high hardness (scratches glass). Commonly found in riverbeds, lake shores, and gravel deposits worldwide.