Zanium
From Tardis Wiki, the free Doctor Who reference
Zanium was an element, only caused by the function of a matter transporter: when a solid body was dematerialised, tiny trace elements in the atmosphere called nistron carbonised and fell like very fine grey snow. It could be smelled even two hours after transmission. (PROSE: The Twin Dilemma
In 2310 when Romulus and Remus Sylvest were kidnapped by Azmael from Earth, Archie Sylvest found a dust-like deposit of zanium and contacted the Interplanetary Pursuit, confirming that it was an extraterrestrial kidnap. (TV: The Twin Dilemma)
The Forge stored zanium in the archive room of their Alpha Facility. (AUDIO: Project Lazarus)