mirabilite en

A hydrated mineral form of sodium sulfate, the sodium salt of sulfuric acid, occuring in nature as colorless prismatic crystals near salt water springs or lakes, and in caves. Mirabilite is unstable and quickly dehydrates when exposed to dry air, turning into the powder thenardite. It owes its name to Johann Rudolph Glauber who dubbed it “sal mirabile” (“wonderful salt”) when he inadvertently synthesized it while working with sulfuric acid and salt. It is also known as Glauber’s salt.