I have a 1980 proof set that I purchased last fall. I set it out on a desk and left it. When I got it, only the penny had some light haze that had formed in the center on the obverse. The rest looked good. May have barely exhibited haze forming. Now the S.B.A, the half and the dime all have white haze forming, obverse and reverse. The quarter seems to have toned a different color altogether. I thought maybe sunlight could have caused it but the haze is forming on the backside of them as well, where there is no direct light. These are still sealed in the mint plastic case. The house temp only changes maybe a couple degrees from time to time. I leave the thermostat set at 70. Question is, how did this set make it this long without damage and now this?
the cases are not air tight. so i would have to guess at something changed in the environment to cause or help the hazing.
probably moisture that was trapped in the air in there, then maybe the sun heating it up. does it look kind of like when you fog up a mirror with your breath?
I hate that haze. Coin dip will remove it. http://www.wizardcoinsupply.com/product/e-z-est-jeweluster-coin-cleaner-5-ounce.html I have dipped roll searching finds that are proofs in this stuff and must say it works great!
Doug : I Believe Doug is 100% correct on this. The very beginning stage of toning. On a non -PL Business strike or a matte proof, it wouldn't be noticed until much thicker layer. On a Proof or a Prooflike coin with mirrors, it is noticeable probably many years or decades before. A color toning zone would eventually follow as the interference layers increase thickness. JMHO, no proof either. Dipping might remove it from proof silver coins, But, your margin of error would be significantly less than dipping a MS coin. The mirrors are there because of the smooth level of the surface unlike a MS where is is like microscopic "^^^^" . The mirrors will dull much easier. Jim
Great. I just ordered a 2000 proof set to leave out on display. Well I hope I don't get a bad experimental batch. Didn't pay much for it anyway. Beginning stages of toning, huh? Well, maybe I can prove this theory one way or the other. This set won't be going anywhere for decades.
