These are the latest 2 to come out of the lot of uncleaned coins I bought a few weeks ago. They were severely encrusted and my nylon brush wasn't cutting the mustard. I bought a brass bristled brush off amazon and WOW did it do wonders. These still have some spots that are dirty but I don't want to scrub them any more with the brush for fear of damaging the patina. Does anyone have any suggestions? Constantius II FL IVL CONSTANTIVS NOB C, laureate, cuirassed bust right GLOR-IA EXERC-ITVS, two soldiers holding spears and shields with one standard between them with o on banner Unfortunately I can't make out the mintmark on this one. I believe it is from Siscia though. Constantine II CONSTANTINVS IVN NOB C, laureate, cuirassed bust right GLORIA EXERCITVS, two soldiers holding spears and shields on either side of two standards Mintmark Epsilon SIS
Since it is from an "uncleaned" lot, I would probably do one of two things 1) let it soak for a couple of more months 2) Get a dental pick and work on the crud. Could also try a sodium hydroxide or potassium hydroxide soak, but that might really strip patina.
That's one thing about ancient folks........they have no regrets when it comes to cleaning.........heck, they've 'rebuffed' (no pun intended ) the 'modern' guy on more than one occasion........