I'll start off my new arrival marathon with two Romans struck from the worst alloy used for coins: billon. Each of these were made at a time when the silver was alloyed to a point that they look worse than the ones a few months later when the metal had more copper and certainly a few months earlier when there was more silver. First is a billon antoninianus of Diva Mariniana, wife of Valerian I who died before he became emperor. Like coins of her husband, earlier coins had enough silver to look like silver but the later ones are a porous mess. This one is not badly struck for this notoriously uneven empress. Roughly speaking, I'd guess her coins will sell for ten times the price of a similar coin of her husband but who wants a common Valerian like this? This is my only Mariniana and probably will be for a long time. Second is a billon argenteus of Maximinus II from Trier (RIC 826 - PTR). This coin is not silver washed 1-2% silver like the common coins of this emperor but a very poor 18mm billon. I believe, in theory, the coin should be worth four of the larger folles of the same period. This was pretty much the end of this denomination which had been started under Diocletian in much better silver. The reverse is Sol in a facing quadriga. Nice ones are not cheap. Show your coins of either type, please. Failing that, lets see your Imperial Billons. For the record, my (not new) Licinius I RIC 825 argenteus is worse silver which makes it a better looking coin since the copper is not hindered by as much silver. These vary enough that some might be found as low grade AE3 coins in the stock of dealers who do not know the types. I was not that lucky.
Sweet OP-additions, Mentor (congrats) Yah, I love the Diva Mariniana, flyin' away on the back of a peacock (man, I love that coin-type) ... sadly, you know that I lost-out on a similar example during the last CNG auction (*sigh*) Ummm, billon Imperial => does this baby cut the mustard? (hubby, Valerian-I)
Nice one, Steve. The Mariniana you missed was much better metal and had good Peacock detail which bidders including you valued over the portrait or legends. The page linked here includes the coin you lost and several others but I see something funny. With few exceptions the coins estimated high went low and the ones guessed low went high. This just shows how hard it must be on the people who write catalogs. https://www.cngcoins.com/Search.asp...R_TYPE_ID_2=1&SEARCH_IN_CONTAINER_TYPE_ID_4=1
Yah, that is kinda funny, eh? => below is the example that I weakly tried for ... it ended-up being the highest of the three examples in that 372 auction (funny) ... I miss it (I'm sad that I didn't score it)
There seems to be a particular ratio of silver to copper that makes the metal look decrepit, no matter how well the coins are struck. As you say, if they were just a little more in one camp or another, they'd be much nicer coins. Here are two of Gallienus that we could probably agree fall into the "ugly billon" category...
And making the point even further, here are two more ants. Valerian of better silver, although clearly billon, and Gallienus with almost no silver at all, which makes the coin a reasonably attractive bronze...
Looking at all these billon coins makes me wonder how well the silver enrichment process would work with silver diluted to this degree? And just how much is too much before the enrichment process no longer works properly and the mint resorts to a silver wash?
That is a good question but there certainly would be a point where enrichment would require removing more copper than would be practical. My guess would be that the limit would be much higher than any of these and probably higher than what we would call billon. Perhaps someone knows a study on the matter. I don't.
i'm not sure where this one falls on the scale, it's fairly attractive coin and doesn't look like its just silver washed. plus i can't keep who made what reforms to coinage when straight. but the picture is actually very good, the color is right on. PROBUS, 276 AD, Antoninianus O:IMP C M AVR PROBVS AVG, radiate and cuirassed bust right, R:ORIENS AVG, Sol walking left, right hand raised and holding globe in left, captives seated before and behind, I in ex.; Lugdunum mint, RIC V 44, 23 mm, 3.7g i'll add this one as well....
