My policy doessn't state anything explicit concerning counterfeit money. AXA is my carrier but they would only cover the first $2000 worth of my collection, after that $8.28 per $1000 per year appraised value of the balance, appraised by an independant party$$$$. Gonna cost a fortune. Cheaper in a SDB.
If your money, counterfeit or not goes up in smoke, you can't prove it real or otherwise anyway.
PD