Cinder

Quick answer: Cinder is how you carry lava. "Cinder is created by destroying Scoria. It can be transported, and then burned with the Flamethrower to (re)create Lava" — the middle step of the game's official lava-moving cycle.

Material Data

The Lava Cycle: Lava → Scoria → Cinder → Lava

The full loop comes straight from the official wiki: "Lava can be frozen into Scoria by combining it with Snow (such as from the Cryoblaster). This can be destroyed with any weapon which will drop as Cinders. Cinders can be carried around with the Grabber or on Conveyor Belts/Launchers. Igniting the Cinder will turn it back into Lava."

Scoria itself never occurs naturally — it exists only as frozen lava. It has 10 HP, takes damage from all seven regular digging tools, and is tougher than Dirt but breaks reliably.

The One Rule That Trips Everyone Up

Reignition is picky: "Cinder will burn, but requires the direct flame of the Flamethrower to melt back into Lava. More passive heat sources will not melt it." If your Cinder refuses to become lava again, this is why.

Whether Pyro Dispenser bursts or the Burner Belt count as "direct flame" is not addressed by any official source (unverified) — the Flamethrower is the only documented ignition tool.

What Cinder Is For

"Turning Lava into Scoria and then Cinder is an early method for moving Lava around your factory" — essential because Lava cannot be pumped through pipes at all.

Its flagship use is the auto-burner: set a Filter to only allow Cinder, place a solid block below, fill the Filter with Cinders and ignite them. The trapped Lava then ignites any Residue running over the top — the burning stage of the gold loop, fully automated.