We propose the symbol ⁂ to represent the fediverse.
...
⁂ is called an asterism. In astronomy, it refers to groups of stars in the sky, akin to constellations. We suggest that it’s a very fitting symbol for the fediverse, a galaxy of interconnected spaces which is decentralised and has an astronomically-themed name. It represents several stars coming together, connecting but each their own, without a centre.
...
@ is the symbol for e-mail. # is the symbol for hashtags. ☮ is the symbol for peace. ♻ is the symbol for recycling. ⁂ can be the symbol for the fediverse.
⁂ is standardised as Unicode U+2042, making it ready to copy and insert anywhere.
Git Repository: fediverse-symbol/fediverse-symbol
logo added to Unicode than reuse an existing symbol. It's not impossible, considering that the Bitcoin symbol (₿) ended up making it.