Pop Rocks are a nostalgic candy. They cross over on all generations. Pop Rocks were first made in the 1950's, combining sugar, corn syrup, and carbon dioxide under high pressure, resulting in the creation of tiny, gas-filled candy crystals. Tear open a pouch of Pop Rocks, dump the rocks in your mouth and the explosion of candy starts. The crackle noises that come from your mouth if you open it, the popping of them on your tongue. This is such a fun candy!