Lava dust is a rare resource obtained with a pump.
Neither a solid or a liquid, lava dust seems to be something in between, having the characteristics of both. It is believed to be a mixture of magma and slime, though this has never been proven. And despite its name, lava dust is only warm to the touch.
On the Ranch:
Deposit lava dust into the Lab's refinery where it can be used for crafting Slime Science gadgets.
Treasure Pods that contain Lava Dust
All of these Treasure Pods also contain 2 Deep Brine
Crates that contain Lava Dust
Only crates dropped by Gordo Slimes caught on a Gordo Snare, or from those dropped by the Crystal, Hunter, Dervish, Tangle and Mosaic Gordos found in the wild, can contain Lava Dust. The chance you get Lava Dust from these crates is the same as its rarity.
Recipes that use Lava Dust
Any Warp Depot
Fiery Glass Sculpture
Dandy Fashion Pod