Atium is a god metal and therefore, with few exceptions, only a full feruchemist can store an attribute in it. Atium can be used to store youth. While storing youth, a feruchemist quickly grows older and receives the physical stat changes associated with their new age but not the mental stat changes. A feruchemist cannot die from old age by storing too much youth at once. Conversely, while tapping youth, a feruchemist quickly grows younger, acquiring the physical stat changes but not the mental stat changes. This cannot prevent them from dying of old age. While not tapping or storing, a feruchemist returns to their normal age.