Huge ban liang 18 grams ? Or fake?

I bought this coin from a metal detectorist as found in Lithuania. If it is true it would be a very interesting historical fact. Or maybe I was tricked and it is a fake? what would be your opinion?

Looks like an early type of Ban Liang from the Kingdom of Qin as they usually weigh over 12 grams. Interesting find in Lithuania, but it may not be historical, most likely someone lost it.

Thanks  so much.  Can you estimate its approximate value, because I can't find information about coins of this size anywhere?

Hartill puts the value at 11/16, or 25 USD.