So, I have been thinking for a while. Trellium. Could it be Atium that has been corrupted. Atium is described as silvery, Trellium is described as a silvery metal with a red cast to it, and dark red spots similar to rust. Red in the cosmere means corrupted and Shalash recognizes that.
The first WoB indicates to me that it would be, but it could go either direction.
The second says that we know the shard the metal came from, it could be from Ruin or Autonomy(Trell).
Please help me expand my theory.
Happy 4th to all the Americans. *Stares at England*