I appreciate all of your comments and input. And yes, the rock has an outer layer of sorts, there are a couple spots where the outer layer is missing. There are cracks all around the whole rock that seem to be that outer layer that is cracked. Two geology professors at a local college said they really didn't know what it is. One of them said it was extremely dense and heavy... my Mom said she thought she said something that sounded like "barium". As a kid I wondered if it was a geode... but they aren't shaped like that. Because of the way it looked, I also wondered if it started out as somethi