Lanthanide
From Wookieepedia, the Star Wars wiki.
Lanthanide was a metallic substance used in armor plating. It could be made into an alloy with duralium. It was used in the exterior shell armor of the Emperor Palpatine Surgical Reconstruction Center and in Palpatine's Chair of Office.
[edit] Behind the scenes
In real life, lanthanides are a series of elements in the periodic table.
