What Magma Core Does and Why Mods Ask For It

A shared library, not a content mod

Magma Core is a small, single-purpose mod that other mods depend on. On its own it adds little you will notice in normal play. Its job is to provide the shared code that dependent mods call into, so those mods do not each have to reimplement the same underlying mechanics.

That is why it shows up in your mod list even though you never chose it directly: it arrived as a required dependency of something else you installed. Removing it will not just disable Magma Core, it will break or crash every mod that lists it as required.

Because it is a library, there is nothing to configure and no in-game items or blocks to seek out. If a dependent mod is installed and working, Magma Core is doing its job silently in the background.

If you are troubleshooting, treat Magma Core like any other dependency: keep it installed, keep it alongside the mods that need it, and check the dependent mod's own documentation first when something misbehaves.