Thermite

Thermite is a quest item in Fallout: New Vegas.

Characteristics
Thermite is a metallic composition of aluminum powder and iron oxide, which produces an exothermic oxidation-reduction reaction known as a thermite reaction, used in demolition and to melt through metals.

Locations
In the quest How Little We Know, Troike mentions he made enough thermite to destroy the entire Omerta weapons stockpile with the tampered light in the basement of Gomorrah. By activating the weapon caches, thermite is used despite never being in your inventory.