I can read the obverse : IMP Quintil, so I guess it is, but I was unable to find the obverse at wildwinds. Dimensions are: 20.5mm 3.42gr I would appreciate your help. Thanks!
@Makanudo ... Yeah, I went to look and see if it were like my Quintillus... Your coin's bust does not look the same as my Quintillus... RI Quintillus 270 CE Ant - Rome mint - Radiate-Victoria RIC Vi 33 Albeit I do not have the same reverse as yours, your coin's bust looks VERY similar to mine of Postumus: RI Postumus 259-268 CE Antoninianus Cologne Oriens ex @TIF
I think the OP coin is probably Postumus. Here's my Postumus - no Quintillus for me yet. It has a pleasing silver appearance even though I understand it's only about 17% silver. Serapis reverse.
Milan according to Wildwinds, but I believe there is some contemporary thinking which may dispute this. My memory is not serving me well on this topic, so perhaps someone with a stronger memory muscle will weigh in.
I asked this question about a different coin of Postumus a few weeks ago. It seems that coins originally thought to have come from Cologne are now ascribed to Trier: https://www.cointalk.com/threads/postumus-mints.308149/
Great catch @Pishpash ! They are very similar bust as Aureolus was minting them in the name of Postumus... RI Postumus struck by Aureolus 268 CE Revolt of Milan Concordia