Hello friends , I have aproblem with precipitating pt and pd from an aqua regia solution that I made from an ore near by , It is giving a colored indication of stannus chloride test so I didn't found any precipitation of au with sadium metabisupfite , so I tested with pt and pd precipitation . I did adding aluminium foil . So I ve got a brownish color powder precipitation , Can any one please guide me on this situation . Thank you and good day