Deutronium is a flammable substance resembling white pebbles with many uses. ("The Girl from the Green Dimension")
The Robinsons spent much of their time drilling for deutronium, as they required it as fuel for the Jupiter 2.
Some species consumed deutronium as food, including the Cyclamen and the People of the Green Mist. ("Attack of the Monster Plants", "Wild Adventure")
Lacking any currency, the Robinsons attempted to buy the freedom of Verda the android with deutronium. Mr. Zumdish said that it would involve considerable expense to refine the substance. ("The Android Machine")
Professor Robinson remarked that he'd never seen deutronium in liquid form. ("The Phantom Family"; "The Mechanical Men")
Creech had a fortune in deutronium stashed on Destructon. ("Fugitives in Space")