Plassnium is a transformed element that was discovered on Telios Prime almost a century ago. Initially, there were very few uses for the rather dense and brittle material, which at that time had been called illantium. Following many experiments on the nature of radiation exposure to several materials, it was discovered that illantium, once exposed to gamma radiation, became transparent to phased matter. This discovery led to the improvement and final design of Telian phased matter beam weapons, as the material made it possible to construct the firing chambers of the devices which had so far been only theoretical. The gamma-irradiated material was labelled plassnium, in honor of the transparent material plas'ss.