Azuremite

 is a blue crystal formed from millennia of psychic energies near element deposits.

Properties
Azuremite is one of two substances that can be refined into the drug suude (the other being residuum), which can enhance spellcasting.

History
Explorers of the Crystalfen Caverns discovered veins of blue crystal called azuremite, which formed due to thousands of years of exposure to psychic energies from the aberrations that lived there before the Divergence. When the crystal is mined and refined, it can also produce suude. Near Yug'Voril there are veins of blue crystal matching the description of azuremite, but Vox Machina couldn't identify it at the time.