igneous
Weathered iron-rich rock, possibly hematite-bearing basalt or ironstone
Uncertain; likely Fe-oxide-rich basalt/ironstone containing hematite (Fe₂O₃), magnetite (Fe₃O₄), and silicate minerals
AI-generated identification · may be incorrectDark reddish-brown to gray, dull-to-submetallic luster, fine to medium grained, irregular fracture, and apparent weathering rind. Hardness is approximately 5–6.5 Mohs; specific gravity may be elevated, especially if magnetite or hematite is abundant.
Identified More igneous →
Explore Weathered iron-rich rock, possibly hematite-bearing basalt or ironstone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark reddish-brown to gray, dull-to-submetallic luster, fine to medium grained, irregular fracture, and apparent weathering rind. Hardness is approximately 5–6.5 Mohs; specific gravity may be elevated, especially if magnetite or hematite is abundant.
Formation & geological history
Likely formed as volcanic basalt or chemically precipitated iron-rich material, later oxidized and weathered at the surface; its geological age cannot be determined from the photograph.
Uses & applications
Common material has little commercial value, though iron-rich rock can be an ore source; attractive polished pieces may be used decoratively or collected.
Geological facts
The reddish coloration commonly comes from hematite or iron-stained silicates, while black metallic patches may indicate magnetite. A magnet and streak test are useful for distinguishing these minerals.
Field identification & locations
Common in volcanic terrains and banded or weathered iron formations worldwide. Test for magnetic attraction and a red-to-brown streak; a laboratory assay or thin section is needed for reliable identification.
