sedimentary

Banded ironstone pebble

Jasper-rich iron formation; chiefly microcrystalline quartz (SiO₂) with iron oxides/hydroxides

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown ochre color with thin white quartz-filled fractures, earthy to slightly dull luster, very fine-grained and compact, with no visible cleavage. The rounded shape indicates water-worn or tumbled material.

Identified September 8, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely derived from ancient chemical sedimentary iron formation or jasper and later silicified; iron formations commonly formed in Precambrian oceans roughly 2.5–1.8 billion years ago. White seams are probably quartz deposited in later cracks.

Uses & applications

Used as a decorative stone, lapidary pebble, paperweight, and occasional jewelry material; attractive pieces are polished or tumbled.

Geological facts

Its iron-rich brown coloration comes from hematite, goethite, or limonite. The specimen is too rounded and weathered for precise identification from a photograph alone.

Field identification & locations

Look for extreme toughness, opaque earthy color, fine grain, and white quartz veining; it commonly occurs in stream gravels and near iron-formation outcrops, especially around the Great Lakes, Australia, India, and South Africa.