Malatium

Malatium, also known as The Eleventh Metal, is a Allomantic Metal discovered by Kelsier. It is classified as External Temporal Pushing Metal.

While Kelsier spread rumors that it was the only thing capable of killing the Lord Ruler, this is but a falsehood. For the metal instead shows you the past of others, or an alternate version of themselves had the past gone differently.

One could say this is the External varient of Gold. Letting you see anothers past as opposed to seeing your own past.