Bitcoin has periodic events. Some events are uncommon, and some are very rare.

Starting with some basics

Casey Rodarmor, the creator of the Ordinals protocol, introduced the concept of defining the first sats mined during key periodic events on the Bitcoin blockchain as rare sats — a classification now known as the Rodarmor Rarity Index.

Over time, the community has expanded this concept to include not only the first sat of these events but also the last sat, referred to as "Black sats".

Rodarmor sats are typically distinguished by a sequence of trailing zeros (e.g., 1982,600,000,000,000), while Black sats feature trailing nines (e.g., 1982,699,999,999,999).

Because both Rodarmor sats and Black sats are emitted at periodic events in Bitcoin's emission schedule, they fall under a broader category known as Emission Rarity.

Understanding Emission Rarity

Emission rarity stems from the cyclical nature of Bitcoin's block emissions. Aside from the "Alpha" and "Omega" sats, all others are classified under the Rodarmor Rarity Index. Most of the Rodarmor rare sats are yet to be mined, and their emission will continue to be gradually released until the year 2140, when the final satoshi on the Bitcoin network is expected to be mined.

Understanding Pattern Rarity

Pattern rarity comes from interesting patterns found in the sat number, sat name, or block number. Palindromes are the most well-known sats in this category, and nearly 90% of all palindrome sats were mined during Epoch 0.

Understanding Historical Rarity

Historical rarity is tied to key milestones in Bitcoin’s short but impactful history. While all historical sats have already been mined, many are still waiting to be discovered by the sat hunters.

Mastering The Art

While the knowledge gathered so far is enough to get started with Rare Sats, mastering the art of discovering hidden rarity traits will hold the key to the most valued treasures.