British maybe? Beyond that, the pic needs to be enlarged wo we see the coin in better detail. Can you crop it so the only thing showing is the coin, and not the CDR it's on?
It seems to be a Dutch ducaton, a 'silver rider', from the northeastern province of Overyssel. It's listed as KM-80 in my older 1st edition Krause with the 1742 date listed at $200 in XF and $110 in VF. If genuine it should weigh 32.78 grams and would contain .9917 of an ounce of silver.
