Re: Cleaning Copper Rock?
Years back also I found some rocks with copper in it on the Upper Peninsula. I cut and polished them the shine will normally last from a few days to a week or so. What I finely worked out was I used a product that is available at most drug stores called �Tarn-X�. Tarn-X is not quite a dangerous as muriatic acid, but you still need to be careful. This is important you need to do the next steps as so soon as possible soaking with baking soda solution. Final as soon as you can get the copper completely dry spray the copper with a coat of �clear coat�, this is a spray that comes in a spray can available at any auto parts store that is used to touch up the clear finish on a car.
Hope this helps.
From Robert Place - September 20, 2010 at 12:19:27