Got this recently. The era of the last tetradrachms for Roman ruler before Diocletians coinage reforms. The coin has two unusual aspects to it, in that the date order is reversed S-L instead of L-S and that Eirene is leaning on what appears to be a lituus shaped column. A coin I have only seen a few images of and I am proud to have one in my collection. Post your Diocletians, Eirenes or anomalies. Diocletian AD 284-305. Potin Tetradrachm (19.5mm, 7.38 g.) Egypt, Alexandria mint, dated RY 6 (AD 290/1). Obv. A K G OYA ΔIOKΛHTIANOC CEB, laureate, cuirassed bust right Rev. Eirene looking left, holding branch and scepter, leaning on a lituus shaped column, SL (date) across field. No reverse legend. Attractive brown patina. Rare variety with Eirene leaning and unusual date order,SL instead of LS
I think that is just the robe rather than a column. It looks like it is trailing off at the bottom. Below are some examples that are similar.
That's a great coin, and interesting date arrangement, as you say. Quite nice for a Diocletian -- the quality control had suffered in recent decades! Here's an Imperial Ant. Nothing too special about it except that it's reportedly ex MA Historical Society / John Quincy Adams (6th American President) and Descendants Collection (Stack's 5 March 1971), Lot 939 (part). Only a minority of the coins were illustrated or described in any detail, and I think the group lots came with a single label/envelope, so like most, this coin has lost any proof of provenance except by attestation of Heritage Auctions and CNG. (Unless the MHS's old inventory in Boston is that detailed, but I highly doubt it.) Incidentally, the ancients should probably be called "Charles Francis Adams Collection" instead. The last mention of J.Q.A.'s ancients is in a letter from Charles Francis saying the box couldn't be located. (The modern coins were found.) C.F.A. bought a great number of ancient coins from Sotheby's auctions in the 1860s while serving as Minister to the UK during the American Civil War. (I think I even know which sale for a different Adams Collection coin of mine, a Republican Quinarius.) (He was also in temporary possession of the ridiculous Groux Collection -- which happens to be a great numismatic story if you're ever bored -- and may have "accidentally" held onto a few hundred after their drama was resolved.) C.F.A.'s son, Henry Adams (of The Education of...) "had no use" for the coins, added none to the collection, and donated it to the MA Hist. Society in 1913, where it remained until they decided security was a problem & sold them in 1971. My Alexandrian Diocletian's are a sorry bunch. On this one at least the name is clear enough to be certain it's him! (A big problem I find when IDing the later ones.) I assume that's Dikaiosyne, as it looks like she's holding scales.