Digging around in my stash of photo chemicals, many of which were given to me, I found a jar of Ferric Ammonium Sulfate and was wondering what it was used for. I searched my Darkroom cookbook and really didn't find reference to it. I googled and found that it was used in photography among other things. One link mentioned toners. I suspect it must have been used in iron toners,but another link mention gold toners. I just deciding on what to do with it or if I might have some use for it in the future? Any ideas? JohnW