Silmaril
From LSWiki
Frankly, I have no idea why this is a material. For a variety of reasons, I think whoever originally designed the Elflords was smoking crack. However, it is, and so:
Silmaril is the name of the variety of magickal gem Elflords possess and use to enhance their guild-granted weapons and armor. It is of incomparible value, surpassing durability, and does not occur naturally.
Information about the original Silmarils of Tolkien lore can be found here.
--Leolla's note -- this was renamed...uh. Something....!
--Arafein's note -- renamed to Silima - see Kill Blue.