Nice $5 score , talesof !
Some turned bowls were 'manufactured' with small 'riffles' in them to facilitate mixing/kneading .
Some 'panners' of placer & dust gold would use riffled wooden bowls too .... this would sometimes result in loss (downstream) of the gold pan ... this led to pretty much standard use of metal pans when panning for gold .
I've seen a fair number of antique metal gold pans that had been 'riffled' with hammers , especially ones hand-crafted by Chinese miners .
