removing/neutralizing verdigris

BigGreek

Is there a safe way to this with copper coins?

lordmarcovan

You could try soaking in mineral oil, I guess. I find a gentle Vaseline rub works nicely on verdigris, and a wooden toothpick to get it out of crevices. Commercial products like Blue Ribbon work pretty well, too.

Of course it depends on the severity of of the verdigris. If there's corrosion involved as well, there's probably not a whole lot you can do.

BigGreek

I have a little on the surface of a large cent. I'm thinking of trying
to remove it myself as its not a super rare or expensive coin. It's
visible under 10x but at 1x it just looks like a black spot.

Shamika

I've heard that if you soak the coin in olive oil for a long time (~6 weeks), it will completely remove it without changing the anything else on the coin. I've not tried it, but at least one board member swears by it.

lordmarcovan

Olive oil is a tried and true (if excruciatingly slow) method.

I would try soaking it a while and working the spot with a toothpick (or better yet, a rose thorn- I hear the thorn is good because it is harder than the wood of a toothpick and it keeps its point longer, but is still not hard enough to scratch a coin. I haven't tried the thorn method before, though.)

Toothpick and Vaseline might be worth a try for starters, and if that doesn't work, try a longer oil soak and maybe the thorn.