Metal detectorists discovered a cache of ancient coins in a field in eastern Poland, according to a CBS News report. Three of the coins are Roman dinars minted between A.D. 138 and 161. These coins bear an image of the face of the emperor Antoninus Pius (reigned A.D. 138 and 161). Another silver dinar is imprinted with the face of his wife, Faustina the Younger, dated to A.D. 141. The face of the emperor Marcus Aurelius has been identified on another dinar dated to A.D. 174.A piece of one coin, which also bears the face of Antoninus Pius and has...