Mirabilite is a naturally occurring mineral composed of sodium sulfate decahydrate, with the chemical formula Na2SO4·10H2O. It typically forms in evaporative environments, such as salt lakes and saline soils, where water evaporates and leaves behind crystalline deposits. The mineral is often found in large, white, crystalline masses. Mirabilite is known for its solubility in water, which means it can dissolve easily when mixed with water. This property makes it useful in various applications, including the production of soda ash and as a drying agent in chemical processes. It is also studied for its role in natural ecosystems and geological formations.