Constantius II, AR Heavy miliarense, Cyzicus. AD 347-355, 5.10 g.

FL IVL CONSTANTIVS PERP AVG, laurel and rosette-didemed head 
right.
VIRTVS EXERCITVS, three standards.

Mintmark dot SMK.

Markoff 2101. Not in RIC, Cohen, Gnecchi etc.
Apparently unique and unpublished. 

With permission of Numismatica Ars Classica, Markoff Collection, Oct 2011, lot 2101.
Estimate: 12,500 CHF.