SINCLAIR STAMMERS / SCIENCE PHOTO LIBRARY SINCLAIR STAMMERS / SCIENCE PHOTO LIBRARY
Specimen of banded ironstone, collected from an open cast iron ore mine at Nsangwenya, Swasiland, Africa. This ancient rock was laid down in every continent due to the availability of oxygen produced by the first photosynthetic organisms such as the cyanobacteria. More than 90% of the Earth's minable iron was deposited between 2500 and 1800 million years ago. This type of rock is variously described as haematite-quartzite, banded iron formation, banded jasper or calico rock.
Model release not required. Property release not required.