Need Help with Qual ysis of an Unknown Salt.?

I am trying to perform an ysis of an unknown pure compound from the Slowinski & Masterton Qual ysis book. I have a salt that is soluble in nothing I have tried so far-- 6M NH3, 6M HNO3, 6 M NAOH, 12 M HCL, 6 M HCL, 6M H2SO4, and a couple more I can add if need be. It seems BaSO4 might be present, given the lack of any solubility seen so far. My salt is white with gray. BaSO4 is white but what would make my salt gray and also not be soluble in any of these reagents? I saw slight solubility (I think) with 6 M HCL. I can answer more on observations too if need be. Any ideas would be great! Thanks!