It is 20mm x 16mm x 6 mm thick, heavy metal probably bronze, definitely bronze in color. It weighs 13.7 grams. The sides you don't see look as if they were crudely broken off, not cut. A 30 minute search of google leads me to believe it could be a piece of Roman aes signatum, basically a proto coin. This piece was bought from a seller that bought it in a large lot of ancients and had no idea what this was. I picked it up shipped to me for 150, cents that is. I think it's really cool!
