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 breathe in lava. You can cancel the Obsidian Skin buff by right-clicking on its icon.

A Water Walking Potion, or better yet, Lava Waders, are viable alternatives to an Obsidian Skin Potion for some purposes, as it will allow you to stand on the surface of lava without taking damage, or even stand in lava without taking damage for up to seven seconds in the case of Lava Waders.