This coin is the same as the series 2 10 BTC 2012 version, albeit with a gold plating added over the Bitcoin sign. It is notable that this coin (this specific image) is proudly displayed by Casascius as his Bitcointalk.org thumbnail image, and is prominently visible on his website. It could be argued that this is among the most visually appealing of Mike Caldwell’s work.
The quality of the gold plating is said to be less than ideal, and was improved upon in the series 3 1 BTC 2013 ‘Gold Rim’ coins. Since these coins were shipped inside capsules, the plating is not an issue as long as they remain inside.
*Mintage figures represent both series 2 and series 2 ‘Gold B’ versions; specific numbers are unknown, but the ‘Gold B’ is ssumed to be more rare. It can be speculated that a total of 500 were minted.