Argyria is a condition caused by improper exposure to chemical forms of the element silver

Silver

Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, silver dust, or silver compounds. The most dramatic symptom of argyria is that the skin

Skin

-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

 becomes blue or bluish-grey colored. Argyria may be found as generalized argyria or local argyria. Argyrosis is the corresponding condition related to the eye.
In animals and humans, silver accumulates in the body over time.