Physical Bitcoins by Casascius

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 alloy bar 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,, or directly into Mt. Gox as a deposit method.  (Casascius coins use the "minikey" private key format, and the main client does not yet support redeeming minikeys.)

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 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


Item Price Quantity Total
Aluminum "Strength in Numbers" Promo Coin (bag of about 500) FREE POSTAL SHIPPING
1.25 inches in diameter, blank back, does not include any bitcoins. Print your own sticker for the back and use it as a business card, or print your own private key sticker and put bitcoins on it.
฿0.39 ฿0.00
Items you won at an auction
Use this if you won items at an auction run by Casascius and are submitting shipping details and getting a payment address. Enter the amount you are paying in BTC before shipping. Please identify the item(s) won, along with the Award Code, in the notes box below. Subscribe to blog to be notified of auctions.
฿     ฿0.00
Shipping Options      
Choose a shipping option
Only Bitcoin is accepted.
TOTAL ฿0.00
Your name:
Address line 1
Address line 2
Postal/Zip Code
Your e-mail: (no spam)
Phone number
If ordering two-factor items,
paste public key(s) or
intermediate code(s) here.

The phone number is requested for FedEx on all shipments as well as international orders on the customs form. 

I accept the Terms and Conditions

Click the button to save your information and get a total and a Bitcoin payment address.

My PGP key