Refined Materials are type of currency that can be used for upgrades, purchasing weapons and weapon slots, unlocking new systems, unlocking artifacts slots.. They can be acquired directly by finding crates and doing missions, but also indirect after recycling your junk.
Steel is a member of the resources and is used in every upgrade for ships. It is the most common material in the game. It is also used to buy all warp paths to different systems. Steel is best found from Executor and Mitrilion Elite left side.
Hydrogen Crystals are one of the resources a player can obtain by recycling junk, completing missions or exploring systems. Hydrogen Crystals are used for level 4 upgrades and elite techs on ships and to buy warp paths to certain systems, most notably Arrenius and Sarkinon.
Iridium is one of the resources that can be created by recycling junk, completing missions or by exploring systems. Iridium is used for level 6 upgrades and elite techs for ships and to open certain new systems. Some good places to farm for it are Experimental Macrophage, gold crates from Mother Brain, and from The Cleaner.
Plasma fluids are one of the resources that can be created by recycling junk, completing missions,or by exploring systems. Plasma fluids are used for level 5 upgrades and elite techs for ships and to open certain new systems.