Today in my chemistry class I performed a lab which involved reaction of iron(III) nitrate with potassium thiocyanate solution to form a colored complex which is measured spectroscopically. Earlier, the formation of this complex was used as a qualitative test for iron, but it did not work well. The addition of the thiocyanate in that lab to a solution shown later to only contain manganese ions produced a white precipitate. Do any other metals form thiocyanates that are not as well known? Cobalt(II) thiocyanate is soluble, however, and so other transition metal thiocyanates can be considered to be soluble as well. The composition of that precipitate is a mystery.