Iridescent Hematite - Elba Island, Tuscany, Italy
Oh, what a treat! Alas, Elba hematite is almost exhausted, but this mineral, in this small island, has helped make great ancient Rome. They used to extract metallic iron from hematite, loading this mineral with coal in clay ovens that reached temperatures of 1300 °C. Blowing air inside the oven with a bellows, oxygen, carbon, and carbon dioxide produce carbon monoxide, which reacts with hematite to give metallic iron and again carbon dioxide.
Fe2O3 + 3CO —> 3CO2 + 2Fe
The metal was then worked extensively in the forge to get the final product.