Magnesium oxide Magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of and consists of a lattice of Mg ions and O ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + HO → Mg(OH)), but it can be reversed by heating it to separate moisture. Magnesium oxide was historically known as magnesia alba (literally, the white mineral from magnesia – other sources give magnesia alba as MgCO), to differentiate it from "magnesia
Ammonium dihydrogen phosphate ADP crystals largely replaced the quartz and Rochelle salt crystals in transducers because they are easier to work than Quartz and, unlike Rochelle Salt, are not deliquescent. Being relatively non-toxic, MAP is also a popular substance for recreational crystal growing, being sold as toy kits mixed with dyes of various colors. Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate (ADP), commonly called monoammonium phosphate (MAP) is a chemical compound with formula . It is a white crystalline solid consisting of ammonium cations and dihydrogen phosphate anions in equal proportions. ADP is a major ingredient of agricultural fertilizers and some fire extinguishers. It