Elemental bones are a lethal poison to the majority of the living species, including humans:
- if it was touched, it would burn the skin
- if it entered the eye, it cause blindness
- if it was consumed, the innards would be dissolved.
Although they are described to "shine an aquamarine light", they are referred to as [Black ash], since the nature of it symbolises death itself.
During the Great War, humans (Imanity) would wear dust masks and fur armour in order to prevent themselves from coming into contact and inhaling Black ash.