Duritanium

Duritanium was a type of alloy used in construction.

Part of the hull of the Intrepid was made of duritanium. 

Parts of the shelter used by Khan Noonien Singh and his Augments on Ceti Alpha V were made of duritanium. 

By 2376, Leonard McCoy's extremities were supported by a duritanium and plasteel framework.