Arcanium

Arcanium (An), commonly referred to as Arcana, is a chemical element most commonly occuring in water sources, lava, and as a biological component. It's the primary source of magic and thaumaturgy in the globe, and its primary biological form, the neurotransmitter arcana, is what propells all individuals with magical abilities. Due to the nature of the globe's current scientific and technological state, both the naturally occuring element and the neurotransmitter are discussed in this singular article; there are very few confirmed differences between the two forms of the element, and scientists don't know a lot about the element to begin with.  

Occurence

Arcanium has naturally occured in various liquid and solid sources throughout the globe, however as there is no known method of producing it otherwise and it has historically been used and processed by arcanists, it has depleted over the centuries and is markedly less abundant than it once was.

That being said, there are still several known 'hoards' or 'reserves' of arcanium: Capris' Ridge, Mount Lune, and the city of Aveaas are all theorized to contain large amounts of arcanium, and the Obsidian and the Etter are confirmed as containing traces of arcanium as well.