sedimentary
Banded Iron Formation (BIF) or similar banded sedimentary rock
Banded Iron Formation
AI-generated identification · may be incorrectAlternating bands of iron-rich minerals (like hematite or magnetite) and silica (chert or quartz). The piece shown has greyish/greenish bands and yellowish/tan bands.
Identified More sedimentary →
Explore Banded Iron Formation (BIF) or similar banded sedimentary rock in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Alternating bands of iron-rich minerals (like hematite or magnetite) and silica (chert or quartz). The piece shown has greyish/greenish bands and yellowish/tan bands.
Formation & geological history
Precambrian age, formed in shallow seas when oxygen levels in the atmosphere increased, causing dissolved iron to precipitate out of the water.
Uses & applications
Major source of iron ore globally. Sometimes used as an ornamental stone.
Geological facts
Most BIFs were deposited between 2.4 and 1.8 billion years ago. They are key evidence for the Great Oxidation Event.
Field identification & locations
Identified by the distinct alternating layers. Often magnetic if magnetite is present. Found in ancient shield areas like the Pilbara in Australia or the Great Lakes region in North America.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary