I found this the other day when I was out. Not sure but was thinking it could be a hammerstone?
Looks identical to this one I found on the internet:
http://www.google.com/imgres?imgurl...dsp=18&ved=1t:429,r:11,s:104&biw=1259&bih=635
Looks identical to this one I found on the internet:
http://www.google.com/imgres?imgurl...dsp=18&ved=1t:429,r:11,s:104&biw=1259&bih=635