Rock candy or sugar candy, also called rock sugar, or crystal sugar, is a type of confection composed of relatively large sugar crystals. American best food saffron rock candy is flavored by natural saffron. (Saffron is a spice derived from the flower of Crocus sativus, commonly known as the "saffron crocus". The vivid crimson stigma and styles, called threads, are collected and dried for use mainly as a seasoning and colouring agent in food. Saffron has long been the world's costliest spice by weight.)