To wash or leave an untouched coin? that is the question. Marcus Aurelius AD 169 - AD 170 Bronze Roman Imperial Sestertius AD December 169 Head of Marcus Aurelius, laureate, right OBV: Head of Marcus, laureate, r. Leg: M ANTONINVS AVG TR P XXIIII (l. up, r. down, As unbarred) REV: Marcus, in military dress, on horse pacing r., holding transverse spear. In front, soldier, helmeted, standing front, holding transverse spear and shield. Behind, three soldiers, helmeted, standing r., two holding aquilae and one holding spear. Leg: COS III (above) PROFECTIO AVG SC (in two lines in exergue)
I would leave it alone. Once you start cleaning it you never know how it will turn out. I have cleaned 100s of ancients and it is always something of a crap shoot.
Cleaning the small deposits will leave a coin that will be questioned as possibly smoothed. The scatter makes it look legitimate. As i is there is a place behind the head that looks like the cleaning went too deep. It is easy to go too far.
I believe in leaving it. Unless it's something truly drastic. I like to think it adds character and many of times, attractiveness. The OP coin is lovely!
I agree. Unless there is bronze disease, I say leave it. Easy to mess up a great coin and if doing no harm, it does not detract from the coin at all.
I would also say leave it as it is, the earth deposits provide a description of a part of the coins history, and eye appeal.
I wouldn't clean it but I would carefully inspect the light green spots. They look a bit powdery. Hope I'm wrong. If powdery (bronze disease), I'd soak the coin in distilled water, lightly brush or pick at the BD spots, dry well, and treat with Verdicare. Store the coin with a desiccant or in an otherwise humidity-controlled environment, and check those spots often. For a coin of this caliber it may be best to have a professional conservator do any treating.
Assuming no bronze disease, I would just leave it alone. I definitely think the earthen look contrast adds value to many ancient bronze coins.
I would monitor for change first, and only then treat for BD. Sometimes one can remove the powder using dry brushes and treat the cause (humidity) and the BD will never reappear, which has happened with a few of my coins.