Is it like a right of passage that you MUST at some point in time make this post?
Search because your EXACT QUESTION has been asked and answered before .. since you're probably not going to search I will sum it up so you can go about your life -
Cocaine is soulable in ICE COLD water but many of todays cuts ARE NOT, so, you can take a sample and do this - add it to some ICE COLD WATER, gently agitate .. if 10% of your mass is "real coke" then you should notice 90% of the shit just remain as a solid .. of course since it's probably been cut by many people, there is a good chance that maybe HALF the mass will disolve - you can filter and throw away the shit that doesn't disolve, then take your fliud (that has the coke) and proceed to either recrystalize the coke, inject it, or freebase it yeilding CRACK ..
Lets discuss the latter.. since you just got GARBAGE I encourage you to just throw it away; or you can give it to a girl (in exchange for a blowjob/sex/love/relationship perhaps) .. but if you really want to dick around with it then why not add some baing soda and proceed to "make some freebase" or "rock up some crack" (NOTE: if you're a raver then the former is your answer - it's not crack .. if you're anyone else thats not full of themselves and clueless about drugs, it's CRACK! .. we have a few good threads on various waysto make your own crack so I encourage you to check them out...
But if you really have some shit thats 90% cut, snort it all or throw it out...