I am pretty much a rank amateur when it comes to ancients. This coin is about 17 mm in diameter and the obverse seems to match the description for Sear #3920, but the reverse does not. I have it as Heraclea mint, but other than that, I am lost.
The style of this coin just is not right for Heraclea mint and Crispus. The PROVIDENTIA legend was used with the camp gate type not a standing figure. I see two possibilities: It could be an unofficial barbarous issue from the period but these are rarely this literate a copy of the legends. The letter forms just do not look 4th century. I suspect it is a modern fantasy - perhaps 19th century???
I wanted to say unofficial too :/ but after looking a the fake reports at forum... Crispus, AE3, RIC - Unknown Obv: DN FL IV CRISPVS NOB C Bust: Diademed, draped holding mappa bust left. Rev: PROVIDENTIAE CAESS Providence standing left holding victory on globe and scepter. Ex: SMH palm branch in field left. Ref: None Example of uncleaned fakes which turned up enmasse in 2003, believed to have originated in Bulgaria. Quickly identified by the crude style, although originally thought to be Barbaric Imitations when first few appeared. Image courtesy Bob Bischoff at Petroni Coins http://www.forumancientcoins.com/fakes/index.php
Obviously the same type so I was off by two centuries. I must say that the coins are no different but any safety we felt from the poor fake patinas in the Bischoff photo is gone now since the coin that started this fooled me into thinking that it had been buried a couple hundred years. My bad. A point here: It is always best to check the Forvm fake reports when you see something strange. These coins are obviously not 'right' but the fake reports tell us just how very bad they are.