Tri-nickolas powder (bottom)
Tri-nickolas powder was, according to the Federation LCARS, a "non-oxidizing chemical explosive used in class-N(2) planetary environments for engineering applications. This substance is unstable in oxygen atmospheres and must be handled in accordance with SFRA 2884.3 safety regulations."
Tri-nickolas powder was available to the crew of the USS Enterprise-D, and was one of the powerful explosives suggested to be used to help free the ship when it was trapped in a Tyken's Rift in 2367. (TNG: "Night Terrors")
Atoms of this material appeared in an okudagram display of explosives listed in the USS Enterprise-D library computer.