Yes, of course it can be cleaned; but since you don't know how; you are most likely going to ruin a nice coin if you listen to someone on this board. The little bit of verdigris on your coin doesn't hide any details and doesn't distract from the overall appearance.
Wow, that really is a fantastic Quintillus. I don't think the green deposits really detract too much. Personally, I would leave it as is, because with something nice like this, the mistakes will be obvious. That said, someone who is good enough with a stereo microscope and pin & scalpel could probably do it. No idea whether the soaking-with-carbonates method would work or preserve what looks to be a nice patina; Victor Clark posted one recently where he removed the obverse ones but stopped w/ some still on the rev. My favorite Quintillus, from the Andrew Short / Orfew Collection, and the Clain-Stefanelli Collection before that (with Elvira's tag?): Here's one with an AETERNITAS reverse (a duplicate ex Doug Smith with his photo, I believe, from Anc. Med. Coins Can. 2):
That’s a great portrait! I agree that I’d leave it alone if you can’t easily just pick off the encrustations with something that’s not going to scratch anything up, like a toothpick or something. Here’s a few of my favorite Quintilli(?)
Bought my Quintillus on a whim during a sale where I picked up some other coins. I figured it'd be a good hole-filler until something better came along. However, the rusty-colored patina makes it stand out amongst my other coins, and honestly this makes it interesting to look at from time to time. It's strange how feelings about coins tend to evolve over time. Not sure if it's chemically similar to those on yours, but mine also has some green blotches.
Quintillus (270 A.D) Æ(S) Antoninianus O: IMP CM AVR CL QVINTILLVS AVG, radiate, draped bust right. R: FORTVNA REDVX, Fortuna standing left with rudder and cornucopiae. Z in exergue. Rome Mint, 270 A.D. 2.65g 18mm Appleshaw hoard 305; RIC 19 var (cornucopiae)
This is a coin that could be totally ruined by "smoothing", however I might be a little concerned about the patina. If hard and intractable, probably no harm. Probing with a toothpick wouldn't hurt and perhaps some VerdiCare might be called for @BadThad
A few things. Thank you for the responses. 1. It definitely will not come off with a toothpick. 2. The toothpick is the most I, by my hand, would ever do to this coin. 3. I would only have a professional or someone with extensive experience touch it. I love the other coins. It’s hard to believe that in only six months on the throne, Quintillus had a beard, lamb chops, a goatee and a horseshoe moustache.
Bronze Coin (AE Antoninianus) minted at Rome during the reign of QUINTILLUS in 270 A.D. Obv. IMP.C.M.AVR.CL.QVINTILLVS.AVG.: Rad., dr. & cuir. bust r. Rev. APOLLINI.CONS.: Apollo stg. l., holding branch and leaning on lyre set on rock. RCS #3242. RICV #9. DVM #3. RCSVIII #11434.
Just have one Quintillus, and for sure I will not clean it Æ2 Antoninianus Mediolanum, August/September-November 270 AD, mintmark T (3rd officina) 18 x 19 mm; 2.637 g RIC V Quintillus 45; Sear 3242A; Cohen 8; Ob.: IMP QVINTILLVS AVG radiate and draped bust right Rev.: CONCO EXER Concordia standing left with standard and cornucopiae. T in exergue Rome used no exergual mark, but Mediolanum did use an exergual "T" mark on two versions of this coin. The exergual "T" mark, officina T(ertia), is attested for use with a truncated inscription CONC EXERC or CONCO EXER or CONCO EXERC and a single-standard type.
