AE tessera, Commemorative Series. 330-354 AD. 15mm, 1.27 g). 

Star of eight rays
O/C · S/C in three lines; all within wreath. 

Bendall, Anonymous, D; Bendall, in NumCirc CXVI.4 (August 2008), fig. 4. 
Good VF, dark green patina. Very rare.

CNG 84, Lot 1522. Estimate $300.
Sold for $900.

With permission of cngcoins.com