> From: Stephen.Pushak at saudan_HAC.COM > Anyone know if Barium at .01% in a substrate is bad? Not necessarily, although barium is typically a contaminant in carbonate minerals (where it substitutes for calcium.) What kind of substrate is this? 0.01% also might be at the limit of detection for whatever analytical technique was used for the assay (you didn't write 0.010%, for example) so there might not be that much barium in the substrate. Craig