Arcolith

An invaluable component in much arcane technology, arcolith is a natural crystal which has an innate ability to channel power from the Myth, much like the metal mythril. The primary use of arcolith is in the construction of mythallars, each of which requires hundreds, or even thousands, of pounds of crystal.
Arcolith forms far underground, usually 150 miles below the surface or more, and mines for it must be nearly three miles deep. Because of how difficult it is to extract, it is a highly valuable resource. Only a handful of productive arcolith mines exist, and they tend to be near the equator: Kassaan and Oristhane are two major exporters of arcolith, though Lar Aslaki's arcolith mines are a notable exception to the equatorial rule. Out of the three, the single-largest producer of arcolith is Oristhane, and the bulk of Oristhane's arcolith is extracted from the area around the free city of Eschen, a nine-hundred-year-old mining town that has grown into a wealthy, exclusive paradise thanks to its arcolith profits.
In its natural form, arcolith is a transparent, milky-white, or blueish-white crystal with a waxy luster that naturally grows in a cubelike formation, similar to bismuth. It is nearly as hard as diamond, so it is difficult to manually process, but arcolith's unique magical properties provide another means of manipulating it. A sufficiently-powerful spellcaster holding a piece of arcolith can cause it to reshape itself, though this is tricky to do and requires significant focus and energy by the spellcaster. This is how most mythallars are constructed.

Type

Ore/Mineral

Value

~250gp/lb

Color

transparent, milky white, or blueish white

Density

~1.5oz/in³ (~2.6g/cm³)