A farmer in Colorado purchased coal and discovered a ring in one of the chunks. Realizing it could be worth a significant amount, he consulted experts. It is estimated that the ring is at least 60 million years old, based on the layers of rock in which it was found. The artifact was named "Eve's Ring". In 1908, the ring was studied using advanced technology. It turned out it had been oxidized for less than a century before being preserved in the coal. Otherwise, it would not have survived until the 19th century. The ring is made of bronze with a gold alloy.