Only the mint mark Delta makes of this coin under Licinius I, a rare one. It was struck in Nicomedia, and I thought it should be listed as RIC VII- 44D. Such a listing could be at Catbite since I couldn't find an exact match on Wildwinds, nor could I precise the degree of rarity.
How does it compare Licinius I Ae 23mm, 6.6g, Antiich 310 AD RIC VI Antioch 133b. R2 GENIO IMPERATORIS Genus standing left holding patera and cornacopiae Altar with star in left field ϵ in right ANT in exergue Some differences and Nicodema and Antioch difference but may give you something to go on.
it's not particularly rare...if you think it matters, it is r1 (11-15 examples) in RIC another example--
True that it's not all that rare, but the large flan size is unusual for that issue. It's not often that you can see a complete circle of dots around the emperor. How much does it weigh?
The coin weighs 2.86 g. I have another one which has an " Engraver's Error " as stated on RIC. It was struck in Alexandria RIC VI- 28 var. That coin has K instead of X on reverse where it should read X over II Mu (12.5). But mine seems to have maybe H instead of X. I didn't shoot the coin yet but I have some scans for the time being. Hope it's rare enough. Here it is. Thanks..
2.86 is in the right ballpark for this issue. Rarity, as reported in RIC, is not really an issue with coins from this time period. Rare officina marks, like the delta on your OP, and engraver's error don't really command a premium with coins from this time period. Still it's nice to have a complete circle of dots on the obverse. I think that, rather than the mint mark, makes your coin kinda special.