To buy Na2SO4 from China, contact [email protected].... Equipment in the factory. Sodium sulfate is the sodium salt of sulfuric acid. Anhydrous, it is a white crystalline solid of formula Na2SO4 known as the mineral thenardite; the decahydrate Na2SO4·10H2O has been known as Glauber's salt or, historically, sal mirabilis since the 17th century.