There seems to be enough detail here that I should be able to figure this one out but I have spent a lot of time with it and I can't seem to find it. Can anyone help me with an ID? Thank you! About 19mm & 10.3g.
This is a tetradrachm of Alexandria, Egypt, issued when the city was under the control of Vabalathus of Palmyria (top). The reverse honors the Roman Emperor Aurelian (bottom). There are similar Roman style antoniniani issued from the mint at Antioch which he also controlled for a short time (270 AD).
To complete the excellent answer by Doug, here is an example of the antoninianus he reffers to : Vabalathus, Antoninianus Antoninianus minted in Antioch, 8th officina, AD 271-272 VABALATHVS V C R IM D R, Draped, laureate and diademed bust of Vabalathus right IMP C AVRELIANVS AVG, Radiate and cuirassed bust of Aurelianus right. H at exergue 2.45 gr Ref : Cohen #1, RCV # 11718 Q
Here is my Vabalathus with a sand patina. Vabalathus (270 - 275 A.D.) AE Antoninianus O: VABALATHVS V CRIMDR, Laureate and draped bust right. R: IMP C AVRELIANVS AVG, Radiate and draped bust right. Antioch RIC-381 20mm 3.3g