I've observed that too. Three years ago I bought several batches of "uncleaned" coins (a misnomer; they were all cleaned to some degree and were 90% slugs). On a few of the utterly hopeless LRBs I tried gentle heating. Well... not really that gentle . I used a propane torch but held it fairly far away and brushed it back and forth. After a very brief time lead boiled out like pimples popping!
Hi, Pish, I am afraid that I am not knowledgeable enough to help you with your query, but I can post my Quintillus. Interestingly, the photo of the Obv. came out a totally different colour to the Rev. I had to 'photoshop' (the Rev.) quite a lot to get them looking even a bit like they are the same coin.
There are people who will correct you for saying anything different than they would say. I use Antoninianus which is no more correct for any coin than any other name made up by collectors. We don't really know that the things were rated at 2 denarii either although the chances of that seem better than not.
Ummm ... sorry, I got nuthin' (I need more coins ... lots more) Man, I hope it turns-out to be a winner, Pish Ummm Mentor, so the last denarii were minted during Aurelian's term as Ruler? (is that why you made the Aurelianus comment?) ... yah, sometime coin-comment whip over my head (*sigh*)
As for this one, I'm puzzled on how to call it : neither double denarius nor antoninianus fits. 1,5 denarius ? 3/4 antoninianus maybe ? Anyway it's 3/4 fricken nice coin ! Quintillus, Antoninianus Mediolanum mint, AD 270 IMP QUINTILL[VS AVG], radiate, draped and cuirassed bust right [M]ARTI PACI, Mars standing left, holding olive branch and spear 2.8 gr Ref : RCV # 11447, Q
It doesn't look broken as much as it looks like the last flan poured out of a group an just ran out of metal before filling the mold.