[Go Gordon]

Almost looks like a megacrystic metamorphic rock. Could explain the rectangular hole on the side. Crystal falling out a long time ago maybe and then sand blasting could have enlarged it? Who knows? Any geologists on the forum?

You mean your not a geologist and still knew about megacrystic metamorphic rock? I need to go back to school...

[AppauledAtAppeasementConservat]

Well I know some terminology from collecting rocks and minerals for a while but nothing impressive. I could be absolutely incorrect in my use of it as well. I just know a little of the basics not much else.

I wish we had a geo ping list so some qualified geo's could share their insights and speculations.