Iron Test Solution (for testing meteorites, CHEM-490-15), ½ fl.oz. (Item 4002). This is a solution of the Thiocyanate, SCN-, ion, that when in the presence of soluble iron produces a strong, blood-red color indicating iron. To use, swab the object with 10%, or stronger, solution of Hydrochloric Acid. Place a drop of the Iron Test Solution on the swab and observe any color changes.