Magnesium sulfate constituents of evaporitic potassium-magnesium (K-Mg) salts deposits. Bright spots observed by the Dawn Spacecraft in Occator Crater on the dwarf planet Ceres are most consistent with reflected light from magnesium sulfate hexahydrate. Almost all known mineralogical forms of MgSO are hydrates. Epsomite is the natural analogue of "Epsom salt". Another heptahydrate, the copper-containing mineral alpersite (Mg,Cu)SO·7HO, was recently recognized. Both are, however, not the highest known hydrates of MgSO, due to the recent terrestrial find of meridianiite, MgSO·11HO, which is thought to also occur on Mars. Hexahydrite is the next lower (6) hydrate. Three next lower hydrates—pentahydrite, starkeyite, and especially
Magnesium silicide in the interior of the unit cell. The coordination numbers of Si and Mg are eight and four, respectively. Magnesium silicide Magnesium silicide, MgSi, is an inorganic compound consisting of magnesium and silicon. It can be produced by heating silicon dioxide, SiO, found in sand, with excess magnesium. The process first forms silicon metal and magnesium oxide, and, if an excess of magnesium is used, the silicide is formed: If an excess of Mg is present, MgSi is formed from the reaction of the remaining magnesium with the silicon: These reactions proceed exothermically. Magnesium silicide is used to create aluminium