sedimentary

Jasper River Stone

Silicon Dioxide (SiO2) with iron oxide inclusions

Hardness: 6.5-7 (Mohs scale); Color: Reddish-brown with grayish overtones; Luster: Dull to waxy; Crystal structure: Microcrystalline/Cryptocrystalline (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Reddish-brown with grayish overtones
Luster: Dull to waxy

Identified May 24, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica-rich sediments or volcanic ash where iron oxides permeate the structure during diagenesis. This specimen is water-worn, indicating it was shaped over thousands of years by fluvial (river) action.

Uses & applications

Commonly used in lapidary for polishing (tumbling), making beads for jewelry, or as decorative garden stones. Larger deposits are used in construction aggregate.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It was highly valued in the ancient world for its supposed protective qualities and ability to control weather.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and its characteristic smooth, rounded shape if found in a riverbed. It feels heavier than plastic of the same size and stays cool to the touch. Found globally in river sediments.

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