Post by rockjunquie on Jan 3, 2014 15:48:01 GMT -5
I never had it effect a stone until I purposely did it to a silver in cobaltite. The silver in the stone turns black. It's a good way to see how much silver is in the stone. Come to think of it- I had a stone with copper in it that turned black, too. Both the stones can be rubbed back to normal, though.
