Ancient Throwing Stone or Tool? South Carolina landscape but am not entirely certain

but am not entirely certain

surely these two have seen some things

Perfect for filling with new powders and tonics

and I've become quite a keen inspector of pieces

with a diameter of 6 inches at the lip and 2

Ancient Throwing Stone or Tool? South Carolina landscape but am not entirely certainI purchased this from a wonderful dealer in New Hampshire whose cabinet of curiosities includes objects decommissioned from museums and science departments as well as gathered from estate collections all over. She didn't know the origins of this stone and neither do I, but it sure looks like a throwing stone to me! If not certainly used as a tool of some sort, with a couple of divets on the bottom one just the right shape for a thumb gripping it.