Hydrogen

Hydrogen is one of the Materials in Mechanic Miner.

Looks
Hydrogen, a pink cube.

Where
Hydrogen is currently not obtainable in the game, although the Balloon is equipped with a full tank of Hydrogen on creation.

Use
Use Hydrogen as a fuel to some of the tech you unlock later in the game. Use Hydrogen to power balloons, and make sure you carry some water with you in case your vehicle runs out of fuel mid-air. Flying isn't very fun when rapid collision looms.