sedimentary

Iron-stained chert or jasper

Microcrystalline quartz (SiO₂), likely limonite/goethite stained

AI-generated identification · may be incorrect

Opaque orange-brown, waxy to dull luster, very fine-grained cryptocrystalline structure, and conchoidal-looking fractures; hardness about 6.5–7 Mohs, with no visible cleavage. The rounded form suggests natural weathering or tumbling.

Identified August 23, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement fine sediment, with iron oxides producing the orange coloration; commonly Precambrian to younger, depending on source. Weathering can release and smooth it in stream gravels or glacial deposits.

Uses & applications

Used as a durable aggregate, landscaping stone, and occasionally as a lapidary material for cabochons and carvings. Its modest appearance generally gives it limited commercial value.

Geological facts

Jasper is an opaque variety of chert distinguished mainly by impurities and coloration; the orange tones commonly reflect hematite or goethite. A streak, hardness, and acid test would help separate it from calcite-rich rock or slag.

Field identification & locations

Common in streambeds and gravel deposits worldwide, especially near volcanic or iron-rich terrains; it should scratch glass but not be scratched by a steel knife. Exact identification is limited by the photograph and visible weathering.