Where does humanity get most of its' iron, and what do these rocks tell us about the ancient Earth? Today, we'll learn about banded iron formations, the backbone of the modern steel industry an important stop in the search for early life and oxygen, and a rock that is impossible to make today. It's rare to find a rock as important to both economics and research. Along the way, we'll take a breath of fresh air, meet orange pond scum in a forest stream, and find a dagger carved from a meteorite. Extra Credit: Find as many steel objects as possible around you, or search for bog iron in a local swamp.