Lava planet

Io is the most geologically active world in the Solar System, with hundreds of volcanic centres and extensive lava flows.

Lava worlds orbiting extremely closely to the parent star may possibly have even more volcanic activity than Io, leading some astronomers to use the term super-Io.

[2] These "super-Io" exoplanets may resemble Io with extensive sulfur concentrated on their surfaces that is associated with the continuous active volcanism.

In addition to tidal heating from orbiting close to their parent star, the intense stellar irradiation could melt the surface crust directly into lava.

Protoplanets tend to have intense volcanic activity resulting from large amounts of internal heating just after formation, even relatively small planets that orbit far from their parent stars.