The Gold Miner's Excavation kit includes a gypsum block and buried within are 4 pieces of iron pyrite. Otherwise known as fool's gold.
Kit comes with a digging tool and brush.
Iron Pyrite was called fool's gold because it has a similar colour and lustre to gold, but is in fact a crystalline form of iron sulphide.
Pyrite can in itself have a beautiful crystalline structure and there are many fine specimens held in private collections and museums.