dipping strips the top layer of the coin and removes some of the original luster. the more its dipped the more is stripped off. when the chemical used is not properly rinsed it leaves a residue on the coin. over several years this residue reacts with the surfaces and causes the blue green red blotchy tones you see here. natural toning normally is consistent and usually begins around the rims and moves toward the devices. the underlying luster would still remain, in most cases, and peek through the toning. on your coin you can see how dull the surfaces look which is indication that the surfaces were altered. hope that helps