Chromium is the external enhancement pulling metal. An Allomancer burning chromium while touching another Allomancer will make their metal reserves vanish. Feruchemists can use chromium to store an unknown quality, and when used as a Hemalurgic spike, chromium steals an unknown quality.
A chromium Misting is known as a Leecher. Chromium acts just like aluminum inside the body, causing enemy Allomancers touched by a Leecher to lose their metal reserves.
Chromium, when used by a Feruchemist, has unknown properties.
When used as a Hemalurgic spike, chromium steals some unknown trait or quality.