Tricobalt

Tricobalt (symbol Tr) is a chemical element, atomic number 129 on the periodic table.

Characteristics and history
Tricobalt, in its most stable form, has an atomic mass of 332, and was discovered by Humans and the Federation for the first time on planet Janus VI in the year 2192. This element is part of the trans-uranic series of heavy elements. 

Tricobalt was of note to Federation science because of qualities as an explosive compound, specifically as being able to create energy release on a scale that caused measurable subspace distortion. (, et al.)

Background
In real-life science, element 129 has yet to be discovered. A placeholder name based on its number, "unbiennium", has been suggested to document the possible existence of this substance. Some models of theoretical science have stated that heavy elements on this scale may be impossible to synthesize or reproduce, and cannot exist in nature. Subspace quantities mentioned in Star Trek may account for the contradiction of this being a natural resource on other worlds.