As of Nov 27,
2013, I suspended sales of items that contain digital bitcoins. Current
items for sale do not contain bitcoins.
Casascius Bitcoins are physical coins you can hold -
and each one is worth real digital bitcoins.
Bitcoin is the most widely
used open-source peer-to-peer "cryptocurrency" that you can send over the
Internet without a bank or a middleman.
Each Casascius Bitcoin is a collectible coin backed by real Bitcoins
embedded inside. Each piece has its own Bitcoin
address and a redeemable "private key" on the
inside, underneath the hologram.
Some of my past products have included:
฿1 Casascius Coin: This is a solid brass coin. Each 1-bitcoin coin is about
1.125inch (28.6mm) in diameter (just bigger than a US quarter but smaller than a
half-dollar) and weighs a quarter ounce. Perfect as a small gift to introduce
someone to Bitcoin. Also available in a
฿0.5 version which is slightly smaller at 1 inch (25.4mm).
฿1 Gold-Plated Fine Silver Casascius Round. This is a 39mm 1oz silver round
accented with gold electroplating on the rim and on the Bitcoin logo, loaded with one digital bitcoin.
฿0.5 and ฿0.1 Fine Silver Casascius Rounds These are a half-ounce
and quarter-ounce rounds (respectively) of fine silver. Diameters are 30mm and 25mm.
Casascius 2-Factor Gold-Plated Savings Bar: Dress your Bitcoins for tomorrow,
make them look their best in your vault today.
Would weigh about 12 ounces if it were solid gold, this is a 4.2-ounce metal
with gold plating. A neat-looking novelty that
looks unmistakably valuable. Available as a pre-loaded 100 BTC bar, as
well as a non-denominated savings bar. Two-factor encryption is available at no
charge. Bar is
80mm x 40mm x 6mm.
How they work: The "private key" is on a card embedded inside the coin and is protected by a tamper-evident hologram.
The hologram leaves behind a honeycomb pattern if it is peeled. If the hologram is intact, the bitcoin is good.
If you have purchased a 2-factor item, the private key is encrypted and will need to be decrypted using your original
preselected passphrase before you can redeem the funds.
The 8-character code you see on the outside of the coin is the first eight
characters of the Bitcoin address assigned specifically to that coin. You can verify
the coin's balance on Block Explorer.
There is a mathematical relationship between the Bitcoin address and the private key inside the coin.
The digital bitcoin is actually located on the public "block chain" stored on the internet, but it is completely inaccessible to
anyone unless the private key from the coin is loaded into a Bitcoin wallet.
To recover the digital bitcoins, there are several ways to
convert the embedded code back into a digital bitcoin so it can be spent over
the internet. Most importantly, none of the methods relies on me or any
other central issuer, due to Bitcoin's completely decentralized design.
The embedded private key code is everything a Bitcoin client needs to find and claim
the digital Bitcoins from the peer-to-peer network.
For example, you can enter (or "import") your coin's
private key code directly into Bitcoin clients such as Armory,
Blockchain.info, or directly into Mt. Gox
as a deposit method. (Casascius coins use the "minikey" private key
format, and the main Bitcoin.org client does not yet support redeeming
Of course, since the face value of the coins depends on the integrity of the embedded key
code, you should only accept Casascius Bitcoins bearing
an undamaged Casascius hologram from others.
E-mail is casascius at
- Frequently Asked Questions
- Casascius Wordpress Blog
- Free High-resolution coin photos
- For more high-quality Casascius-related photos suitable for press use, go to
gettyimages.com and search for Mike Caldwell or Bitcoin.
- More about Bitcoin: We Use Coins.
- Casascius Coin trackers (made by fans)
- I only accept Bitcoins for payment for these items. I do not accept any form of national currency such as Dollars or Euros for my products.
However, you may be able to buy Casascius Coins from others on eBay for such currencies.
- Please note that I am relatively slow to ship products! Delays of 7-10
days may be common, I consider myself mainly a wholesaler. Things that
slow me down include: my other responsibilities, other Bitcoin-related activism
and projects, the unusual and often inconvenient procedures I go through to keep
my products and bitcoins secure, and the fact that I might need to create or
engrave your items before I can ship them. Please consider shopping from
resellers, eBay, or BitMit for fastest service.
- Casascius LLC Terms and Conditions