igneous
Iron-rich vesicular rock, possibly weathered scoria or ironstone
Likely oxidized basaltic scoria (Fe-oxide-bearing volcanic rock); exact identification requires testing
AI-generated identification · may be incorrectDark reddish-brown, rusty orange, irregular and porous, with dull to earthy luster; likely mostly iron oxides plus altered basaltic silicates. Estimated hardness about 5–6, but weathering may make surfaces friable; no obvious cleavage.
Identified More igneous →
Explore Iron-rich vesicular rock, possibly weathered scoria or ironstone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark reddish-brown, rusty orange, irregular and porous, with dull to earthy luster; likely mostly iron oxides plus altered basaltic silicates. Estimated hardness about 5–6, but weathering may make surfaces friable; no obvious cleavage.
Formation & geological history
If scoria, it formed when gas-rich basaltic lava cooled rapidly, likely in the Cenozoic or younger volcanic activity; the rusty color reflects oxidation of iron. It could alternatively be limonite-rich ironstone or industrial slag, which cannot be excluded from the photo.
Uses & applications
Common scoria is used as lightweight aggregate, landscaping stone, and abrasive; ironstone may be an iron ore. This small rough fragment has negligible commercial value.
Geological facts
Vesicles are gas bubbles preserved in lava, while orange-brown coloration commonly comes from hematite and limonite coatings.
Field identification & locations
Check for a lightweight feel, natural vesicles, a fine-grained dark interior, and streak or magnetism; a strong glassy luster, perfectly rounded bubbles, or metallic inclusions may suggest slag. Common in volcanic regions and iron-rich soils.
