MAGNENTIUS. 350-353 AD. Æ 27mm (8.55 gm). 
Ambianum (Amiens) mint. Struck January-August 
353 AD. 

Bare-headed, draped, and cuirassed bust right
Large Chi-Rho, A-w across fields.
Mintmark AMB dot. 

RIC VII 36; Bastien 136; LRBC 20. 

With permission of yourkcoins.com