Vitamin B-12 has this element at its heart; an element not seen in too many other biological roles. This element is one of the minority of elements with a German name, coming from the word for "goblin". In many of the radio and print stories, this named the exclusive club that Lamont Cranston would spend time wining and dining at when he wasn't fighting crime in the guise of The Shadow. The primary pigment in Chinese porcelain since the 8th century is this color, as is that of Delftware (one of the stripes of the flag of the Netherlands is of this specific shade).
Cobalt