Many collectors might have a note redeemable in gold or silver, but how many actually have a note made of gold or silver?!
I just acquired this 23K gold and silver legal tender note from Antigua and Barbuda. These are fairly cheap to purchase ($30 CDN or so) and are a great conversation piece. They are unique, but not terribly rare. The $100 series features famous pirates. The note pictured features Captain Morgan - the very same pirate a popular rum is named after.