I was worried about BD, given the lurid green color, but the green stuff is very hard, not powdery at all. Digging at it a bit, I was not able to dislodge anything. You can see where an earlier cleaning left external deposits (not pits). Whatever it is, the stuff is hard, like coin stalactites. But I'll keep an eye on it. This was one of those eBay orphans nobody wanted (for obvious reasons), but I had hankered for a half follis from Cyzicus with the big "K" serving as part of the mintmark. When it came in the mail I was pleasantly surprised at how large it was - here's the full attribution (green not noted): Justinian I Æ Half Follis Year 18 (544-545 A.D.) Cyzicus Mint DN IVSTINIANVS PP AVG, helmeted, cuirassed bust facing, holding cross on globe and shield, cross to right / Large K; cross above, ANNO left, XЧI/II right, Y/Z below. SB 208; DOC 187a; MIBE 121. (9.10 grams / 29 x 27 mm)
LOL, AWESOME, @Amit Vyas ! Mine left a bit too much VO5 in their hairdo... Just a GOOBER in his hair... RI Quintillus 270 CE Ant - Rome mint - Radiate-Victoria RIC Vi 33
