Magnesium sulfate manufacturers offer a wide range of magnesium salt compounds, including magnesium sulfate heptahydrate, magnesium sulfate monohydrate, and anhydrous magnesium sulfate, which are commonly encountered. However, there are many other types of magnesium sulfate, all categorized by their crystal structures. It is reported that crystalline hydrates with 1, 2, 3, 4, 5, 6, 7, or 12 water molecules can be formed. At -3.9 to 1.8°C, magnesium sulfate heptahydrate precipitates from a saturated aqueous solution, while at 1.8 to 48.1°C, magnesium sulfate hexahydrate forms. Between 48.1 and 67.5°C, magnesium sulfate pentahydrate precipitates. Hexahydrate undergoes eutectic fusion between 87 and 92°C, forming pentahydrate or tetr hydrate, which then converts to trihydrate at 106°C. The trihydrate transforms into dihydrate at 122 to 124°C, and dihydrate magnesium sulfate becomes stable monohydrate at 161 to 169°C. Monohydrate magnesium sulfate precipitates when the temperature is above 67.5°C.