sedimentary

Tumbled jasper or chert pebble

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

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown to reddish-brown with a waxy to dull luster, opaque appearance, and no visible cleavage. The rounded form reflects natural beach abrasion rather than crystal structure.

Identified September 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed when silica-rich fluids replaced or cemented sediment, with iron oxides producing the warm coloration; age cannot be determined from the photograph. It was later rounded by stream or wave transport.

Uses & applications

Commonly collected as a beach stone, lapidary rough, or polished pebble; attractive pieces may be used for cabochons, beads, and small carvings. It has little industrial value at this size.

Geological facts

Jasper and chert are varieties of microcrystalline quartz and can be difficult to distinguish visually from iron-rich quartzite or volcanic rock without testing. The surrounding deposit appears to be a mixed alluvial or beach gravel.

Field identification & locations

Test with a steel file or glass: it should resist scratching and may scratch ordinary glass; a streak test should be pale or white, not reddish. Common in gravel beds, river channels, and beaches worldwide.