Filanium

Filanium is a rare mineral native to the world of Anodunos and appears in Ultima Underworld II.

Description
Filanium was highly prized for its use in medicinal and alchemical preparations, and many natives of Anodunos would partake of filanium-rich mud baths, believing them to promote good health. It was partially due to the prevalence of filanium deposits near the Anodunian city-state that the northern kingdoms of the realm sought to conquer it, hoping to exploit this natural resource for themselves.

During their quest to dismantle the Guardian's blackrock dome, the Avatar would have need of filanium mud, as it figured in a ritual which would allow them to bind an air djinn into their body.

Trivia

 * Bathing in the mud, especially after treating it with the oil, will give humorous reactions from many characters commenting on the Avatar being coated in the mud.