Normal examples of the 2007-W platinum coins show the word FREEDOM (on the reverse) as polished, brilliant letters in contrast with the frosted, unpolished ribbon. In February 2011, a collector, Jason Fishman, reported finding an example of the $100 denomination with frosted, unpolished letters. The Mint confirmed the existence of this variety, claiming it was a pre-production piece "...inadvertently placed in the production stream during preparation for an internal audit." According to the Mint, the following numbers of frosted FREEDOM coins were released:
$100 - 12
$50 - 21
$25 - 21
$10 - None
As of March 7, 2011, only a single example of the Frosted FREEDOM $25 Platinum Eagle has been discovered.
Sources and/or recommended reading:
Martin, Eric. "Mint Wrongly Releases Pre-Production Coins", Coin World 52, no. 2655 (February 28, 2011), 1 and 38.