Electric lava

Covering much of Titan is a sea of electric lava. It is nothing like Earth lava, having more of a liquid consistency, and crackling with electrical energy. When cooled, it turns into energy crystals.

The Transformers cartoon
The Titans lived on an island surrounded by electric lava, though it seemed that the only reason they didn't leave was from fear of the Sky Gods. The Fire God's lair contained some electric lava, which caused the formation of energy crystals in the caves. After Omega Supreme crash-landed there, he was left dangling over a deadly ocean of the stuff, and it was only when Perceptor returned with a bag full of energy crystals that he was able to narrowly escape plunging into the stuff. He later helped the Titans escape their island by extending his track as a bridge over the electric lava so they could cross to the next island.