Silver Inclusions

[Nathaniel N2]

I've done mostly bronze cleaning in my time and what silver I have cleaned has been very simple, just soft dirt coins or green bits that both come off with lemon juice, q tips and patience (mostly the last one). As a collector of modest means who enjoys the cleaning hobby, the chance to buy a pretty coin and work to restore it is intriguing. I've found one I may be interested in, pictured below. To clean such a coin what would you recommend? I don't know what the black substance is. Horn Silver? Iron? Would the best way to treat such a coin be lemon juice? MSR? Horn remover? Sandpaper (Don't worry I would never) I would love to hear about any similar coins you have cleaned and what results can be expected.

[SC]

Not something I have ever done.  I have a couple in this condition - though plain denarii - in my "to do" pile.

Worth reading through the threads as there have been similar ones discussed before. 

I think people have used lemon juice on the black too but am not sure.

SC

[Nathaniel N2]

I'm trying to get a few test denari right now. I would hate to mess up this type of coin, not that lemon juice would really hurt it.

[Nathaniel N2]

I officially bought the coin. I'll have to detail my cleaning efforts. Any advice is appreciated!

[Nathaniel N2]

The looks a lot better in hand than it did online. So far I've looked at some distilled water and probed the black portions with a bamboo skewer. They appear soft, the bamboo being able to leave a mark. I tried a fiberglass pen and this seems to take off some material slowly. I would prefer not to polish the coin and so don't want to go over everything with the fiberglass pen. Is this horn silver then? I tried applying lemon juice with a q-tip, when no change occurred I tried a 15 minute soak followed by a q-tip. No material was removed.

Let me know your thoughts on the best treatment route!