Boronite

Boronite was a rare mineral ore used in the synthesis of Omega molecules. The Borg were able to synthesize a single Omega molecule using a quantity of boronite, but they were unable to repeat the experiment as they never found another source of the ore. 

A Vostigye space station destroyed in 2373 by astral eddies was constructed from sarium, boronite, and carbon-60 composites. 

Boronit