I know little about coins - just have a question. About 40 years ago when my son was a youngster, interested in collecting, we visited Greece. In an "old art store", I asked if they had any old coins. The man in charge shook his head and then blinked and indicated "wait". I could see him in his backroom going through pocket in an old coat. He returned with the following, and I paid a small amount for it. This coin is about size of a US nickel... worn and flat around edges and no longer perfectly round due to age...copper color....cant see image on one side ...but on other is a very visable cross with round ball shapes on the end of each arm of the cross. There are other decorative markings but not easy to describe. I went to library and looked through coin books but I could not find any with a cross. A modern coin collector said ....it was probably early Christian....he also mentioned: don't lose it ! ! Possiby I could supply photo Annette
That could easily be a lot of things. We'll really need a picture to determine what it is. If anything at all is visible on the more worn side, even if you can't tell what it is, please show that, too. If you have a scanner, you may be able to use that. Just remember to set the dpi as high as you can and crop the picture down to just the coin.
I believe this is what they call Anonymous Class I Byzantine. The rulers did not put their image or name on the coin but showed Jesus and a cross. Last I heard these were assigned to Nicephorus III (1078-1081) but that could be out of date. Start research there. You won't get this sort of thing in Greece today. They frown on selling antiquities to tourists. Everything you will be offered will be a fake (that's legal). Compare yours to: http://www.wildwinds.com/coins/sb/sb1889.t.html Condition is everything on these. Collectors like eyes on the portrait. On the linked list above note the coins in good shape (7,8,9) are in good demand.
Best I can tell, Doug Smith has it. It's not a particularly valuable coin, but definitely nice for a souvinir. You're probably the first person I've heard of who managed to purchase a legitimate ancient or medieval coin in Greece.