First off that's a great find. But man that's a pretty dangerous way to be digging for em. Diving a pick axe through a beautiful coin or relic would be an absolute shame. And rubbing a nice old coin with the thumb can potentially make some micro scratches that will detract from the look and value of the piece.
I'm not trying to lecture here it's just a couple tips. That is a hell of a nice find. Still looking for a gold coin.