A Glass rod, stirring rod or stir rod is a piece of laboratory equipment used to mix chemicals and liquids for laboratory purposes. They are usually made of solid glass, about the thickness and slightly longer than a drinking straw, with rounded ends. Like most laboratory glass, stir rods are made of borosilicate (commonly known as pyrex).
A stirring rod is used for mixing liquid. It can help decant the liquid from a container while the solid still remains in the flask. It is easier to keep a precipitate from the bottom of the beaker as it decreases the chances of solid agitation. By pouring it slowly, it is important especially when dealing with potentially dangerous chemicals reacting very quickly. Moreover, it can induce crystallization in a recrystallization procedure. The glass rod is scraped when there is the solution containing inside the flask. It also helps break up an emulsion in an extraction.