Banded Tiger Iron or Ironstone, is a sedimentary rock from the Precambrian age. It has repeated thin layers of many iron rich deposits. They are found in Australian and also Minnesota. Discussions of the sea water formed layers were rich in iron and layed down during a period of time where iron oxides were formed and layered during changes in the earths climate and oceans. Stromatolites are essentially little fossils formed by algae but there is still debate as to how all this is formed. The red bands of iron are quite pleasing to look at and seeing all of the layers that were formed by minerals and little creatures.