It appears to be missing the clad layer. I've seen them from time to time on Fred Weinberg's site for about $125, but those had been certified. Your coin appears to have discolored a bit. Was it found in circulation? Chris
The coin appears to be as thick as a normal quarter. Copper toning has invaded the obverse face. Both observations indicate that this is not a missing clad error. I suspect the coin is discolored or oddly toned.