Well we'll get carbon dioxide off,so you might be  iridium carbonate  or ytterbium, we've got a powder which may be ytterbium car carbonate or ytterbium sulphate and you  never heard of this stuff, ah carbonate  carbonate and maybe, maybe ytterbium carbonate doesn't give off carbon dioxide with acid, but there is a very good chance it does cos all the others you've ever heard about do.