Tacitus, Billon double radiate

IMP CM CL TACITVS AVG, Radiate, draped and cuirassed bust right
CLEMENTIA TEMP dot, Mars walking left holding olive branch, spear and shield, star in left field
Mintmark: IA
Tripolis mint, RIC V (1) 214 var (dot on rev)
IA mintmark = contains 10% silver, value was double that 
of a normal antoninianus. 

Submitted by Peter Dearing, July 2009.