sedimentary

Iron-rich jasper or ferruginous chert

Microcrystalline quartz (SiO₂) stained by iron oxides, chiefly hematite and goethite

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque reddish-brown to yellow-orange, earthy to dull/waxy luster, fine-grained and noncleavable, with conchoidal fracture. The rounded surface appears naturally weathered rather than crystalline.

Identified September 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Most likely silica-rich sediment or chemical precipitate later impregnated by iron oxides, commonly during groundwater alteration; exact geological age cannot be determined from the photograph. It may also represent ironstone or a weathered jasper pebble.

Uses & applications

Used as ornamental stone, lapidary rough, tumbled stone, and occasionally aggregate or pigment; attractive polished pieces have modest collector value.

Geological facts

The red coloration generally comes from hematite, while yellow-brown zones commonly reflect goethite or limonite. A steel file should scratch it only with difficulty, whereas glass can usually be scratched by fresh edges.

Field identification & locations

Common in weathered gravels, iron-formation terrains, deserts, and stream deposits worldwide. Confirm with a streak test (red-brown), hardness test, and ideally specific gravity; a strong magnetic response would suggest magnetite-bearing ironstone instead.