We are very excited to announce that we have just purchased a small group of 2001-P Sacagawea Dollars that were struck with an experimental rinse by the U.S. Mint in Philadelphia.
This experimental rinse/finish attracted much attention when it was discovered on 2001-P Sacagawea Dollars. Coin World attempted to contact the Mint to get the details on this experimental process, but Mint officials refused to comment. The June 25th Issue has a detailed article on this discovery.
This discovery is also featured in Numismatic News in their June 5th Issue. They were the first to report on these experimental Sacagawea Dollars. CoinFacts.com, one of most popular online coin references, is featuring the Experimental Sacagawea Dollar as their "Coin of the Week".
As everyone knows, the year 2000 Sacagawea Dollars, which was the first year of issue, were plagued with spots, discoloration, and tarnish, even when pulled from bags or rolls from the bank.
The Sacagawea Dollar has an alloy layer on each side of the copper core. These two layers are manganese bronze, a composition the U.S. Mint has not used since Wartime Nickels were being struck in the early 1940's. The Mint experienced many problems with the Wartime composition, which peeled, laminated and was not mixed properly.
A similar situation occured in 1999, when the Mint was experimenting with the composition, layers and finish for the alloy to be used for the Sacagawea Dollar. The end result was an overall composition of 88.5% copper, 6% zinc, 3.5% magnesium and 2% nickel.
There have been several articles in Coin World in the last year which have described in detail the problems that the U.S. Mint was having with the composition and finish of the new Sacagawea Dollar. In one of the recent articles, Michael Fahey of ANACS describes the finishing process for the burnished Sacagawea Dollars, explaining that the rinse was "used to remove any surface residue from the coins, and to prevent spotting."