The source of the Sentran arcstone is a closely guarded secret. The Empire has had a steady supply of high-quality arcstone for the last few centuries. There are other mines, all heavily guarded, scattered across the continent. The Imperial Army transports the arcstone from mines to the capital with river barges, finally reaching the Imperial Docks. The Dwarven Entente have at least one buried somewhere in their mountains. Another is believed to be in the middle of the Sandsea where the Elves are busy mining.
The Arcstone is a key component used by Magewrights in the construction of more complicated devices, from levitators to lighting.