Byzantine Empire, Andronicus II & III, Joint reign 2 February 1325 - 24 May 1328 A.D. 
  Rare at this weight. This coin and the referenced Dumbarton Oaks 
example with the same sigla (symbols) are considerably heavier than 
normal for the type (c. 4 grams). DOC V comments on their heavy thick 
flan (6.37 grams). 

SH37428. Gold hyperpyron, DOC V 502, SBCV 2461, VF, very heavy flan, 
weight 5.649 g, maximum diameter 23.4 mm, die axis 180o, 
Constantinople mint, 2 Feb 1325 - 1328 or possibly to 1330 A.D.; 
obverse Nimbate Virgin Mary orans, within city walls, four castles 
forming walls, 3 pellets over K left, 3 pellets over X right; reverse 
Andronicus II on left and Andronicus III on right kneel facing, 
Christ stands behind, blessing, hands over heads; ex CNG 41, March 
1997, Lot 2461; SOLD  

Contributed by Online store of the Forum Ancient Coins, April, 2012