So I got a rock/jewelry tumbler for my birthday. Excited to try it out, especially to try to tumble some Petoskey stones. After some research, found a lot of sites that recommend only polishing by hand, as the stones are so soft. But there are a couple of sites that have some instruction, so I will give it a whirl. Hand polishing really does a number on my hands!
During my research, I came across a few sites that showed pictures of live coral similar to the coral that Petoskey stones came from. So cool!