How to remove black deposit from Denarius

[OWL365]

How can I remove these black deposits from this coin without damage or scratching.They appear to be on the surface on the face and around the lettering.(looking with a 10x loop) Very hard black spots.
Thanks
Mike

[casata137ec]

I'd say 5 minute lemon juice soaks followed by brushing with a soft bristled nylon brush. Repeat until satisfied. Rest in dw overnight. The entire process shouldnt take longer than an hour if you are taking your time.

Chris

[mihali84]

I'd say 5 minute lemon juice soaks followed by brushing with a soft bristled nylon brush. Repeat until satisfied. Rest in dw overnight. The entire process shouldnt take longer than an hour if you are taking your time.

Chris

Chris what would you recommend for a coin that has a nice grey toning (that i would like to keep) but also areas of black deposits like the coin above?  Soaking and scrubbing would most likely remove the toning also, correct?  So far i have tried using a toothpick (too soft) and an x-acto knife (too sharp, scratches).

Thanks
Mike

[Robert_Brenchley]

You'd be lucky to get them off without sacrificing the toning in the short term. It will soon tone again, though!

[casata137ec]

You could try to dab the lemon juice on with a toothpick just to the areas affected and then reducing with a bamboo skewer (I have also had luck with those plastic drink "swords", they do not seem to be hard enough to scratch the material, but are harder than the acid reduced crust)....but that would take a ton more time (not a big deal) AND leave shiny silver spots where the crusties once were...which would be odd.

Like Robert said, it will tone again soon enough.

Chris

[mihali84]

Thanks for the advice Robert and Chris. That is a good idea to use the little plastic drink swords, or even the little plastic toothpick that's in my swiss army knife.   But as you pointed out Chris, it will leave a shiny spot no matter what.  I might have to suck it up and get rid of the tone all together, whatever is best for the coin in the long-run i guess.  It can be fun to see the toning come back, though it is a slow process.

Mike, i would like to see how your coin comes out after it's cleaning, maybe you can post some AFTER pictures.

Regards
Mike