Found this coin. Doesn't sound like a usual quarter. Tarnished well. Any info? I read there were some 1965's struck with the wrong material. J
You need to weigh the coin. That's the only way you will figure it out. I'll bet it's a normal quarter that is just toned.
Yes to Environmental Damage. 1965 was the first year of the new Clad Layer over Copper core. I metal detect and have seen that these quarters buried under soil, dirt, and sand will look as yours does.