Magnesium sulfate decomposes into magnesium oxide (MgO) and sulfur trioxide (SO). The heptahydrate can be prepared by neutralizing sulfuric acid with magnesium carbonate or oxide, but it is usually obtained directly from natural sources. It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. Magnesium sulfate is a common mineral pharmaceutical preparation of magnesium, commonly known as Epsom salt, used both externally and internally. Magnesium sulfate is highly water-soluble and solubility is inhibited with lipids typically used in lotions. Lotions often employ the use of emulsions or suspensions to include both oil
Magnesium chloride made from solar evaporation of seawater. Anhydrous magnesium chloride is the principal precursor to magnesium metal, which is produced on a large scale. Hydrated magnesium chloride is the form most readily available. MgCl crystallizes in the cadmium chloride motif, which features octahedral Mg centers. Several hydrates are known with the formula MgCl(HO), and each loses water at higher temperatures: x = 12 (−16.4 °C), 8 (−3.4 °C), 6 (116.7 °C), 4 (181 °C), 2 (about 300 °C). In the hexahydrate, the Mg is also octahedral, but is coordinated to six water ligands. The thermal dehydration of the hydrates MgCl(HO) (x