Satin Finish, Burnished Coins and Specimen Grades...At times, the U.S. Mint has produced and sold "Satin Finish" coins that are different to the normal circulated examples. The main difference is the finish applied after the coins are struck. They appear matte, unlike their proof counterparts, which have reflective fields. They are generally struck in higher quality, compared to the coins for mass circulation, and sold direct to collectors from the U.S. Mint.
Ian Russell on Sun, May 26, 2019 07:04:10 AM
These were issued in Special Mint Sets from the 1960s, and then again in the 21st century as part of Mint Sets, Commemorative sets or as a standalone issue.
1964 SMS Sets (which are very rare - we recently sold a 1964 Kennedy Half Dollar SMS for over $85,000!).
2006-W Silver Eagles (in a MS or Burnished Look), which were issued individually as well as part of the 2006 20th Anniversary Silver Eagle Set. They differ from the mass-produced bullion Silver Eagle, since the SP coin has a "W" mint mark.
2006-W Gold Eagles (in a MS or Burnished Look), which were issued individually as well as part of the 2006 10th Anniversary Gold Eagle Set. They differ from the mass-produced bullion Gold Eagle, since the SP coin has a "W" mint mark.
2014-S Kennedy Half Dollar in Silver. These were issued as part of the 2014 Kennedy Silver Set of Four Coins. It is the only way the 2014-S Kennedy Half Dollar was issued.
2016-W Gold Mercury Dime (for the 100th Anniversary of the Mercury Dime). This is the only way this coin was issued.
PCGS, NGC and ANACS refer to these coins as Satin Finish, Burnished and/or Specimens - they have changed over the years, however, they are all interchangeable.
PCGS recently changed (in the past few years) to calling all of these types of coins Specimen (ie. PCGS SP-70), as opposed to SMS MS-70.
View SP/Specimen Graded Coins at GreatCollections