There have been a number of one-tenth BTC pieces, but one of the first was the bhCoin “10 bitCent” brass piece in late 2013. I’ve had some series two bhCoins for a while, but only just recently tracked down one of the series one brass coins. It delights me.
The series two coins which came out a few months later are also great, nickel-plated to create a fine silvery shine, though mine did get gently scuffed during the no-doubt-tumultuous journey from Argentina.
Neither series has an especially bold design, but that’s part of their charm. They’re clean, straightforward coins produced by enthusiasts in very limited numbers, only about 100 of each run.
There are pictures of an opened bhCoin series one here.
The folks at bhCoin have since moved on to create a 2-factor coin, and we look forward to their next project.
Standard disclaimer: It’s always, to some degree, a bad idea to let anyone else have access to a private key which controls any of your bitcoin wallets; in a sense, it goes counter to the bitcoin system itself. Once someone else has handled the key which controls your funds, you have to trust both that they exercised adequate security procedures while handling your key, and that they have not save copies of your key to exploit at some point in the unforeseen future. While some (such as Mike Caldwell of Casascius) have established trusted reputations, newer operators can only prove their trustworthiness over time.