CalciumOxide, commonly known as burnt lime, lime or quicklime, is a widely used chemical compound. It is a white, caustic and alkaline crystalline solid at room temperature. As a commercial product, lime often also contains magnesiumoxide, silicon oxide and smaller amounts of aluminium oxide and iron oxide. In its pure form, calcium oxide occurs as white crystals, white or gray lumps, ora white granular powder. It has a very high melting point of 4,662°F (2,572°C)and a boiling point of 5,162°F (2,850°C). It dissolves in and reacts with waterto form calcium hydroxide and is soluble in acids and some organic solvents.Calcium oxide is usually made by the thermal decomposition of materials such aslimestone, that contain calcium carbonate (CaCO3; mineral calcite) in a lime kiln. This is accomplished by heating the material to above 825 °C, a processcalled calcination or lime-burning, to liberate a molecule of carbon dioxide(CO2); leaving CaO. This process is reversible, since once the quick lime product has cooled, it immediately begins to absorb carbon dioxide from theair, until, after enough time, it is completely converted back to calcium carbonate. When quicklime is heated to 2400 °C (4300 °F), it emits an intenseglow. This form of illumination is known as a limelight and was used broadly in theatrical productions prior to the invention of electric lighting. As slakedlime, it is used in mortar and plaster. Lime is also used in glass productionand its ability to react with silicates is also used in modern metal productionindustries (steel in particular). It is also used in water and sewage treatmentto reduce acidity, to harden, as a flocculent, and to remove phosphates andother impurities; in paper making to dissolve lignin, as a coagulant, and inbleaching; in agriculture to improve acidic soils; and in pollution control, ingas scrubbers to desulfurize waste gases and to treat many liquid effluents. Ithas traditionally been used in the burial of bodies in open graves, to hide thesmell of decomposition, as well as in forensic science, to reveal fingerprints.It is a refractory and a dehydrating agent and is used topurify citric acid, glucose, dyes and as a CO2 absorber. It is also used inpottery, paints and the food industry. Furthermore, quicklime is used inepidemics, plagues, and disasters to disintegrate bodies in order to help fightthe spread of disease. CaO is a key ingredient in the nixtamalization processused to create corn hominy and masa or tortilla dough. In ancient India, beforethe discovery of soap, it was mixed with sand and used to clean one's body,while it was also used to build houses. It is also used in compounding as wellas for filler purpose at times.