This sparkly specimen came from an ancient sea bed that existed 75 to 85 million years ago. Pyrite pieces such as this occasionally wash out of the chalk in a geological formation known as the Selma Group. They are usually thought to be fish coprolites. However, when it comes to coprolites that have been pyritized, it is really hard to tell if they indeed have fecal origins. This is because anything organic (in this case the poop) is completely replaced by mineral. So all we can go by is shape and location. This has the right shape and comes from a fossiliferous location.