When first introduced, most of the Sacagawea Dollars were covered with unsightly spots and other discolorations. In order to overcome this, it is known that the Philadelphia Mint performed van­ous tests to elimmate this problem In early 2001, some “different” looking Dollars started to appear and it has been determined by several variety experts that the mint subjected a small number of these coins to an “experimental rinse” to eliminate surface spotting. This explains the difference in color and texture when compared to “regular” Sacagawea Dollars.