Adamask

Adamask (アダマス鋼) was a magic alloy from YGGDRASIL.

Description
In the Web Novel, the alloy is a standard component to the maid outfits worn by the Pleiades. The skirt of the maid outfit possessed a magic black metal board over it, increasing its defensive properties. The board and even Yuri Alpha's chest-plate were made of the same materiel which was composed of three metals: magically enhanced steel, Adamask metal, and Galvoln.

Abilities
Adamask metal was comprised of mithril and beliat.

Trivia

 * In the Web Novel, the composition of the maid outfit is described, however in the Light Novel its materials are omitted.