Anonymous Third Siliqua, Time of Constantine. 330 AD. 12 mm, 1.04 g. Constantinople. 

Pearl-diademed, draped bust right. 
Large K within beaded border.

Bendall 4; Mazzini 287; Goebl pl. 10, 144.

With permission of Roma Numismatics Ltd, March 2015.
Very Rare. Estimate: £1,000.