Walt Puryear wonders if this was a millstone.

Attached is a photo of a broken milllstone I found recently by shoals on the Middle Oconee River near Athens, Ga. What has me puzzled is that the grooves are elliptically concentric and would not move grain toward the stone perimeter. Could you, or possibly one of you members, shed any light on this mystery? Is it indeed a millstone or perhaps the beginning work on one?

Thanks for your consideration.

Walt Puryear
Athens, GA USA

Torleif in Finland replied:

A rotating millstone would normally have a hole in the middle. The grain was filed through the hole in the upper stone and the central shaft would pass through a hole in a wooden bung in the hole of the lower stone.

Even the most primitive rotating hand querns have a wooden peg holding the stones centered to one another.

Looking at the spalting the stone looks pretty soft. Millstones were preferably made from a hard rock like granite. Granite millstones were traded over wide areas in those parts of Europe where granite isn't found because sandstone would add unhealthy amounts of sand to the flour. Settlers surely must have carried that knowledge across the sea to America.

Consequently I am pretty sure this isn't nor was it ever intended to become a millstone.

I have no clue to what it is. Preshistric or 20th century. No clue.

Torleif
Finland