
sedimentary
Iron-rich concretion or weathered ironstone
Goethite–hematite-bearing ferruginous concretion; exact identification requires testing
AI-generated identification · may be incorrectHardness approximately 5–6.5 Mohs; rusty brown, earthy to dull/submetallic luster, irregular granular texture, and no obvious cleavage. The rounded form and dark iron-oxide patches suggest a dense, weathered concretion rather than a crystal.
Identified More sedimentary →
Explore Iron-rich concretion or weathered ironstone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness approximately 5–6.5 Mohs; rusty brown, earthy to dull/submetallic luster, irregular granular texture, and no obvious cleavage. The rounded form and dark iron-oxide patches suggest a dense, weathered concretion rather than a crystal.
Formation & geological history
Likely formed when iron minerals cemented sediment around a nucleus during groundwater alteration, followed by weathering and rounding; age depends on its host deposit. Common in soils, river gravels, sedimentary beds, and lateritic environments.
Uses & applications
Primarily a collecting specimen or educational sample; ironstone may be used locally as low-grade iron ore, aggregate, or decorative material, but this small piece has no practical industrial value.
Geological facts
Goethite and hematite commonly produce red-brown streaks and earthy coatings. A strong reddish-brown streak on unglazed ceramic and noticeable density support an iron-rich composition.
Field identification & locations
Commonly found in Australia, India, Brazil, Africa, and many sedimentary regions worldwide; identify with streak, magnetism, density, and a fresh broken surface. It could also be a terrestrial iron-rich pebble, not a meteorite.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary