Hi Peter, Check this link. Also, if you are asking about a specific piece, many have been plated, including proof coins. This should help, though... I have not heard anything specifically about an S mint proof being struck on a planchet like this but S mint circulation issues that have been plated are often confused as proofs. http://www.coinfacts.com/silver_dollars/anthony_dollars/1999p_one_dollar_experimental_planchet.htm Have Fun, Bill
Nice. Thanks for the info Bill. Nah, this one's not plated, it was right out of the box from the mint to me. Yea, I still have a stack of boxes from the mint, some going back ten years, that I've not even opened yet.
Could be toning. It doesn't always effect each coin equally. I've seen many nice, gold toned proofs that were stored in there original boxes for years. That is just a suggestion as a possibility. A good picture might help. Anything is possible in a sealed set
Howabout a flatbed scanner, I can adjust the color to be accurate....if you have the ability to scan the coin
You might have been on to something....It would have been a jackpot. It seems like it's a normal coin though with some nice toning so it's still pretty nice
Never heard of one and I think it would be highly unlikely. The brass planchets came from one supplier and the coppernickel from a different one, and I would think the production area for the proof SBA's would probably be well away from the production of the Sacs. There are transitional errors on the business strike Sacs and SBA's as MrBrklyn has pointed out, but I don't think there would be any on the proofs. (If there was I would not expect the mirrors on the the coin to be very good because the planchet would most likely have not received the polishing that the copper nickel planchets received.