Can organisms be metallic?

All terrestrial organisms utilize metals, with significant amounts of the lighter ones and traces of the heavier ones.

There is even an animal, the scaly-footed gastropod, or Chrysomallon squamiferum, that profusely makes use of iron in its own organism.

It is a species of marine snail that lives near hydrothermal vents on the bottom of the Indian Ocean between 2,400 and 2,800 meters below sea level.

Their shell is a unique construction made up of three layers.

The middle layer acts as a padding to absorb the mechanical stress and energy generated by an attack, making the shell much harder to break.

The innermost layer is composed of aragonite, while the outermost layer is made of iron sulfides. Even the foot is armored on its sides with iron mineralized structures.

It is the only known organism to incorporate copper sulfide into its skeleton (both in the exoskeleton and in the shell).