A crystallizing dish is a type of laboratory glassware used in the process of crystal formation and purification. It is typically a shallow, circular glass dish with a flat bottom and wide rim that allows for easy observation of the growing crystals. The dish is used to hold a solution of the material that is being crystallized, and the solution is left to cool and evaporate slowly, leading to the formation of solid crystals.

Once the crystals have formed, they can be harvested and purified through additional processes. Crystallizing dishes are commonly used in chemical, pharmaceutical, and materials science applications for the production of high-purity substances, such as salts, sugars, and metals.

The shallow, wide design of the dish allows for easy observation and manipulation of the growing crystals, making it a key tool in the process of crystal formation and purification.