Malatium is an alloy of atium and gold. The exact use is unclear; it allows an Allomancer to see either who another person was in the past, or who they could have become if they had made different choices. This metal is referred to in legend as the Eleventh Metal. It is described as being silvery white in color and porcelain-colored.
Flaring malatium allows an Allomancer to see not just a malatium shadow of a person, but seems to give them a glimpse into the Spiritual Realm, allowing them to see a vision of a past event in another person's life by seeing their Connection and their past.[nb 1]
Malatium, when used by a Feruchemist, has unknown properties.
When used as a Hemalurgic spike, malatium steals some unknown trait or quality.
After becoming Harmony, Sazed thinks that legends about the "Eleventh Metal" were made up by Ruin in order to help Kelsier's crew kill the Lord Ruler. Sazed made such conclusions because even after becoming god, he didn't find any evidence of the existence of these legends before Kelsier's journey. In the story The Eleventh Metal, Kelsier discovers notes on malatium after he defeats Antillius Shezler. Given Shezler's questionable sanity and Ruin's ability to manipulate text, Ruin could easily have created these rumours himself, as part of his plan to escape his prison.
Malatium is different from other allomantic metals, in that when it (and presumably the other Atium alloys) is burned, it provides the power itself rather than drawing upon Preservation, since it is of Ruin. 
- Given the only circumstance in which this effect is seen, it may be a result of flaring malatium at the moment of death and transition to the Cognitive Realm, rather than a result of simply flaring the metal in and of itself.
|The Metallic Arts|
|Arts||Allomancy · Feruchemy · Hemalurgy|
|Concepts||Metalborn · Snapping · Savants · Metalminds · Twinborn · Compounding · Blessings|
|Constructs||Steel Inquisitors · Koloss · Kandra · Chimeras|
|Base Metals||Iron · Steel · Tin · Pewter · Zinc · Brass · Copper · Bronze · Cadmium · Bendalloy · Gold · Electrum · Chromium · Nicrosil · Aluminum · Duralumin|
|God Metals||Atium (Malatium) · Lerasium · Ettmetal · Trellium|
|Era 1 books||Mistborn: The Final Empire · The Well of Ascension · The Hero of Ages · (Mistborn: Secret History · The Eleventh Metal)|
|Era 2 books||The Alloy of Law · Shadows of Self · The Bands of Mourning · The Lost Metal · (Allomancer Jak and the Pits of Eltania)|
|Shards||Preservation · Ruin · Harmony|
|History||Classical Scadrial · Final Empire · Catacendre · Elendel · Southern Scadrian|
|Magic||Metallic Arts (Allomancy, Feruchemy, Hemalurgy) · Metalborn · Mistborn · Misting · Savant · Ferring · Twinborn · Compounding · Atium · Lerasium · Ettmetal|
|Other Media||Mistborn Adventure Game · Mistborn: Birthright · Mistborn film · Mistborn: House War|