Erchius Crystal

Erchius Crystals are a vanilla Starbound item, but the Frackin' Universe mod adds new functionality to them - specifically, through the Extraction Lab.

When the crystals are processed through the extractor, they produce usable Liquid Erchius Fuel in a 4:5 Crystal to Liquid Fuel ratio to put in your spaceship as you normally would with what you find on outer moon planets.

They can also now be found in massive deposits on Crystalline Moon planets, as well as in smaller Erchius Crystal mini-biomes located rarely on other planet types with a greater chance of popping up on planets with a higher risk level. These biomes are doubly known for their tendency to spawn decent amounts of Lunari Crystal Shards, so there are plenty of valuable and useful materials to harvest in these areas.