Magnentius - CHRISTOGRAM! rare and heavy (ME2417)

This reverse was meant to incite the Orthodox Christians of the West against the Arian Constantius II, who intended to reclaim the western provinces. -- Coinage and History of the Roman Empire by David L. Vagi

Magnentius, AD 350-353. Bronze Follis (22 mm, 4.85 g.). Lyons. DN MAGNENTIVS PF AVG, bare-headed, draped and cuirassed bust of Magnentius to right. Rev. SALVS DD NN AVG ET CAES around large Chi-Rho between A-w. S at lower left, star at lower right. Mintmark off flan FPLG RIC 174