Freshwater clam of some sort.
Edge of lake, amidst pebbles and aquatic plants. Sandy Creek Park.
I don't think this is an Asian Clam. It's very dark brown, not greenish. I also don't think Asian Clams are that common in my area. It could be, though; I know next to nothing about clam species.
Lat: 34.03, Long: -83.38
Spotted on Jun 2, 2012
Submitted on Jun 3, 2012