Fraznium

Fraznium is a gold-colored metal which may be used to bypass certain types of magical force fields. It appears in Ultima Underworld II.

Description
While the exact magical functioning of fraznium was never explained, the mineral was employed on Tarna and in the realm of the Scintillus Academy as a means of bypassing mystic barriers. Individuals wearing fraznium artifacts could pass through such obstructions unhindered and could thereby be distributed to those meant to have access to restricted areas guarded by a force field.

In the prison tower on Tarna, fraznium gauntlets were employed in this fashion to grant access to the high-security prisoner Bishop, and the Avatar would have the opportunity to smuggle a pair to the man and thereby ensure his freedom. A fraznium circlet could also be found in the instructors' quarters of Scintillus, and appeared to be intended to allow its wear to access the university's ethereal vault.

Trivia

 * A goblin blacksmith on Tarna mentions that fraznium is a particularly hard to work with metal, likening its consistency to wax.