Cocaine, water, a pinch of baking soda.
Put them all in a spoon and heat the bottom of the spoon with a lighter or any open flame. The mixture will sizzle and an oily mass of slightly different color, will start forming in the liquid. It should all clump together. Clump or not, once you see the oily mass form, remove the flame and as you do so take a metal poker type object to swirl around the oily mass in the spoon, to grab any stray oils that didn't clump into the main puddle. As you're swirling the oily parts should all grab on and clump together as its hardening. Keep swirling the poker stick around, until all of it hardens up and is attached to the poker. You're going to want to swirl it around kind of quickly so the stuff doesn’t harden unattached to your poker stick. It will still be good wherever it hardens up, but you don't want to have to fish it out of the water, it's easier if you scoop it all onto the poker.
The mixture in the spoon can (and should) be tossed out. Remember after you smoke your rock, the stuff on the spoon is history, it is not crack, you did not miss any on there. It's time to go buy more, because you will anyways. And no you'll never match how the first hit felt, no matter how hard you try.
Welcome to the wonderful world of jonsing... Just saying.