This symbol, sometimes referred to as a cruciferous globe or "globus cruciger", represents The Earth or "The World" in Alchemy. It is typically used in the context of "the Created World" as in the following passage from La Clef Du Cabinet Hermetique:

"The philosopher should imitate the nature that God has formed via the commerce of heaven and earth, imitating God in the creation of the [world]." *

* Boke, C. Koopmans, J. Duc Perez, J. (2020) La Clef Du Cabinet Hermetique / The Key to the Hermetic Sanctum. Auckland, New Zealand. Rubedo Press