Thanks for the replies pertaining to my little bottle mystery! I took another picture of it at a different angle to show the depth of the depression. You guys are coming up with some good ideas.
It is a very interesting mark, and a lot of snuff bottles from this time period have impressions on the bases. I have seen several variations with circles and they were thought to have been blown with a coin in the bottom of the mold,and the variations that suggested that a coin had been placed in the mold you really could not tell for certain that it was in fact a coin. Just for a laugh maybe mine had an arrowhead placed in the bottom. How cool would that be. Red I had never really thought about selling my snuff. Do you want it because of the little mystery?