What is blue frosting?(snorting)?

I recently found out that a group of my closest friends is snorting what they call blue frosting. They all seem to have changed as far as their attitudes and behavior go and I am extremely concerned. I have tried to research what blue frosting is but keep coming up with nothing. I have been told by a few people that it is a form of meth and by another that it is a highly refined, potent version of cocaine. Others have said that it could be a kind of bath salts, or even pills. If you have any idea what blue frosting is please help, also any signs, symptoms, or affects that you know of would be useful and appreciated!