Banded Iron Formation (BIF)

Tumbled, as seen in this video: https://youtu.be/yJVM0ldAdxw

This specimen of banded iron formation (BIF) has been collected, cut and tumbled by us right here in Western Australia.

Banded iron formations (BIFs) are composed of interbedded layers of iron-oxide minerals and chert.

Banded iron formations are 1.5 to 3.8 billion years old which makes them the earliest known rocks.