Claudius II, AE antoninianus. Rome. 3.3 g.

IMP C CLAVDIVS AVG, radiate, cuirassed bust right.
MARTI PACIFERO, Mars standing left, hokding olive branch and spear.
X in right field.

Pedernec (F) hoard 291 (this coin). Not in RIC, Cunetio etc.
Very rare.

Image from the Pedernec hoard.