Polyduranium

Polyduranium is a material used by several states and races, mainly for defense.

In 2153, polyduranium was encountered by Enterprise in the doors of a Delphic Expanse sphere and in the hull of an Osaarian ship. 

The hull plating of the USS Defiant (NX-74205) (I) included a mix of polyduranium, kelindide, rodinium and toranium. 

Polyduranium was also used in a bulkhead on the bridge of the Defiant. In 2371, Ornithar expressed an interest in it but he believed it had no real value. 

Polyduranium is also used in the casing of Klingon bat'leths.