Rock candy is a very simple hard candy made by allowing a supersaturated sugar syrup to evaporate slowly (sometimes for up to a week), during which time the sugar crystallizes into chunks. The shape of these crystalline formations matches for shape of the sugar molecule. Over time, this shape is duplicated millions of times to create sugar crystals large enough for humans to see, touch, and taste. The crystals can be formed around any rough surface; strings or small sticks are most commonly used. "Stir Sticks," "Swizzle Sticks," or "Crytal Sticks," are wooden sticks covered with rock candy used to sweeten drinks (like iced tea). Small rock-candy crystals can be used as a fancy sweetener for tea, coffee, and other beverages. Food coloring and flavoring can be added to create a wide variety of interesting rock candy crystal designs.