When the sacagawea coins came out in 2000 there was a lot of spotting on the coins. The US mint worked up some experimental rinses and never heard any more about it. But does anybody know how well they worked out longer period of time? I never have seen Sacagawea or President dollar coins circulate or in any collections. Anyone notice those coins turning color or showing spots in later production years or was the rinse a good fix?
I believe the problem was due to an improper rinse that had nothing to do with the manganese content in the coins. Chris
They were experimenting with the rinses because of the spotting ! Then they started coating the coins after minting - that didn't work either. To the best of my knowledge they still haven't found anything that works. All of this can be read about at smalldollars.com
I've been collecting the small dollars and can tell you they definitely haven't gotten rid of the spotting. It's still on the new coins. It's hit or miss though - sometimes there will be spots and sometimes not. But nobody's changed the leopard's spots yet...