I just found this coin searching through coin rolls and noticed it was missing the copper strip on. Not sure what you would call that error....if it is even considered an error.
Weigh it. Struck on silver planchet? Drop it on a table, and see if it sounds different than another junk quarter. Silver sounds tinnier if you know what I mean.
something to remember with Statehood Quarters is that some were sold after being plated in both gold and platinum. The platinum ones are tricky, because they look like the clads, but are missing the copper on the edge (because it's been covered up). These coins are generally treated as damaged by the numismatic community. Yours looks like it may have been plated at one time. weighing the coin is the best way to determine what it is. Hope that helps