Obsidian Skin Potion

The Obsidian Skin Potion is a buff potion which buffs the player with Obsidian Skin. The buff grants immunity to lava, Hellstone and Meteorite for 4 minutes as well as providing the ability to breath in lava. You can cancel the Obsidian Skin buff by right-clicking on its icon.

A Water Walking Potion is a viable alternative to an Obsidian Skin Potion for some purposes, as it will allow you to stand on the surface of lava without taking damage.