Fediverse emoji

TL;DR: What is the best (or good enough) emoji to represent the fedivers?

I'm updating my union section's website [^1] (wordpress) and I want to add a link to the mastodon account of a territorial grouping using an emoji. This territorial grouping has an account on mastodon and hubzilla, it abandoned corporate social accounts (x, insta…).

[^1]: I'm from Catalonia, where most of the unions are federated/confederated industrials unions and 'Seccions Sindicals' are the organizational structures of the union in each of the companies.