Dilithium

From FEInfobase

Dilithium as an element is a member of the hypersonic series,occurring primarily as a crystalline mineral. Mostly used in the warp drive systems of many star ships. Dilithium regulates the matter/antimatter reaction in a ship's warp core because of its ability to be rendered porous to light-element antimatter when exposed to high temperatures and pressures. It controls the amount of power generated in the reaction chamber, channeling the energy released by mutual annihilation into a stream of electro-plasma.

A very rare element Dilithium was found on very few planets. As such the element is a very rare and costly substance. Due to certain tactics utilized during the Borg war dilithium of any sizable or pure usable quantity is very very rare. Only two known planets are known to have any left. The only declassified source Rura Penthe has a substandard quality dilithium left in it's remaining sources and was relocated from Klingon space into a more secure location for extraction of the remaining sources. Rura Penthe is the federations last real source of dilithium while exploratory mines are being started elsewhere.

Being used in more increasing quantities is Trilithium a "created" substance with properties similar to Dilithium.