Black rare
The last sat of a difficulty adjustment period: the last sat of a block whose next block's height is a multiple of 2,016, other than at a halving.
How a sat qualifies
A sat is black rare when it is the last sat of block h (offset subsidy - 1) and h + 1 is a multiple of 2,016. Block h is then the last block of a difficulty adjustment period, and the very next sat is the first sat of the next period: a rare.
Tiers in the black family are exclusive: black epic > black rare > black. When h + 1 is also a multiple of 210,000, the block ends a halving epoch too and its last sat is a black epic instead. A black rare is never counted as plain black.
The first black rare is sat 10,079,999,999,999, the last sat of block 2,015; the sat after it, 10,080,000,000,000, is the first rare.
Pairs with rare
Every rare has a black rare just before it, and every black rare a rare just after it: both skip the same boundaries, the multiples of 1,260,000 blocks, where the first sat is legendary (mythic at block 0) and the last sat before it black epic. So the two categories have the same total.
A black rare that is also an omega, such as sat 10,079,999,999,999, is not in the Black omega category, which holds plain black sats only.
How many
Will ever exist: 3,432. Mined so far: 482. Extracted, held alone in small outputs: 122.
Supply and market
| Category | Will exist | Mined | Extracted | Last sale | Floor |
|---|---|---|---|---|---|
| Black rare | 3,432 | 482 | 122 | 4,900,000 sats | 3,899,670 sats |
As of block 972,427. Prices are per sat.