Coin with Actual Piece of Concorde Heat Shield in it, Tristan da Cunha
This coin celebrated the 20th anniversary of Concorde in 2009, it’s gold plated and each coin produced contained a tiny piece of Concorde’s titanium alloy heat shield, collect them all and build your own miniature Concorde!
via 25 Bizarre Coins that are legal tender « AdvanceLoan Finance Blog.
There’s stranger and more bizarre, but this was one of the more interesting ones.