I sat and searched through a few hundered cents on more than one occasion,, yawn. Always noticed that there was black residue on my fingertips when done. I was wondering exactly what the black residue on my fingers was. Any ideas? Just plain dirt?

I've heard that some of the machining oils used in the coining process are somewhat toxic/carcinogens.

drop dead mojo?,,,Bad mojo?,, kinda bad mojo?,,, neutral?,,, ahhh, go ahead and lick your fingers?

It stinks too!

I think most of it is probably just dirt and grime from being handled by everyone else and their brothers.

Yeah I'd get that too, in addition to that ever so pleasing copper smell. Good thing I don't search those $50 boxes anymore

Same...I think it's just regular old dirt. I guess you could always dump them in a bucket of water with Dawn and let it clean them for a while.....er I mean conserve them for a while.

Surely, you get your hands all black. Probably just through a lot of dirt. Can't imagine how much bacteria you can get

After I have been through a pile of cheapo coins, I dumped it in a bucket of water with detergent. The next day, the water was sure black

Use latex gloves or vinyl gloves next time. Your finger tips won't be black when you are done.

Some of the "dirt", I believe, just comes from the metals left from the minting process. Even brand new rolls will leave you fingers dirty. Nickels and the Copper nickels seem to be the worst.