Tridenite was an energy ore far cleaner and safer than uranium or any other isotope used for providing power. Vast quantities of the ore existed on Shad, which was in fact the only source of tridenite in Quadrant J-221. They supplied the ore to twenty other planets in the region whose economies and industries depended on it.
In 2258, the Klingon Empire incited a civil war on Shad in an attempt to cut off the tridenite supply and thus pave the way for the conquest of the quadrant. The Loyalist Coalition, however, ensured that the ore trade continued until the war finally ended in 2276. (TOS novel: The Covenant of the Crown)