Proctiv's breach crystal sphere

Proctiv's seal crystal sphere was a powerful arcanist spell that permanently shut off a whole crystal sphere against access by spelljamming ships.

It was actually the reverse version of the name-giving spell Proctiv's breach crystal sphere, which removed an earlier-cast seal crystal sphere, thus opening up portals through that crystal sphere again.

The material component for this spell was a spelljammer with a tonnage of 100 tons, including a major helm.