I picked this coin up this weekend from a collector at a local flohmarkt. He had it marked as a Justinian I, but I'm not sure it was labeled correctly as I have had difficulty locating it on Numista. It is 3 grams, around 20-21mm. Front facing figure with a beard, and large cross on the back. Copper Nummi? The price for this one was very good regardless. Also picked up a nice Basil II Follis, which was easily identified. This one was not.
Hello @Homer2. Welcome to CoinTalk Ancients. Your coin looks like a Byzantine anonymous follis. Anonymous folles were minted from 969 AD to 1092 AD. They were called "anonymous" because the Byzantine Emperor's portrait did not appear on the coin, and the Byzantine Emperor's name did not appear on the coin. They always showed Jesus Christ on the obverse. Looking in my Sear book "Byzantine Coins And Their Values", it looks like your coin is Sear 1889, which is a Class I (The letter "I", not the Roman numeral "I") Anonymous Follis, minted during the reign of Nicephorus III (as @ancient times mentioned), who reigned from 1078 AD to 1081 AD. It looks like your photo of the reverse is upside down, as @BenSi mentioned.