Gravitonium

Gravitonium is a rare element (so rare that many believe it does not exist) appearing the Agents of S.H.I.E.L.D. It distorts gravity's pull on objects, allowing it to be practically weightless. When it is in the full-scale power generator, it attracts anything near it to its core. Physicist Dr. Franklin Hall devoted his life's study to studying Gravitonium. When he powers the generator in order to take down Ian Quinn, as well as many innocent people on the island, Coulson stops him and Dr. Hall falls into it, becomes trapped, and becomes Graviton, a Marvel villain. The current location of this machine is in an unknown S.H.I.E.L.D. security vault.