Etymology The pigment was discovered circa 1700 in the German state of Prussia by a paint-maker named Diesbach.
1
Chemistry, Inorganic chemistry, Natural sciences, Physical sciences An insoluble dark, bright blue pigment, ferric ferrocyanide (equivalent to ferrous ferricyanide), used in painting and dyeing, and as an antidote for certain kinds of heavy metal poisoning.
It is well known that Davy doubted the elementary character of iodine and Mr. Reade's soluble Prussian blue gives us some reason to believe that the great chemist may be correct.1847, editorial staff, “Patent Inks and Salts of Gold”, in Scientific American, series 1, Volume 3, Issue 10, page 80:
2
A moderate to rich blue colour, tinted with deep greenish blue.