What is the value of a copper quarter if the year is in the forties?

Would have to know WHY it is copper. In the 1940's there was no copper core in the quarter, so it can't be a lamination error. If it was struck on a cent planchet, it would be obviously undersized and worth up to $150. If struck on a planchet intended for some foreign coin, it could be worth several hundred dollars but it would be very difficult to locate an interested collector. If it just has a copper color because a high school physics class was experimenting with electroplating (my class only used dimes and pennies) or has had a reaction to contact with some chemical it is still worth about $.75 to melt for the silver content.