is manufactured from limestone, a calcium carbonate mineral (CaCO3), by heating it to a high temperature (about 20000 F) to separate and drive off the carbon dioxide (CO2) from the carbonate (CO3 ) molecule, leaving Calcium Oxide (CaO) This is called calcination or burning
Oxide of calcium; the white or gray, caustic substance, usually called quicklime, obtained by calcining limestone or shells, the heat driving off carbon dioxide and leaving lime
painting - executed on dry plaster The fresco pigments are mixed with lime water or slaked lime, and/or the wall is wetted down with lime water until the plaster softens or a paste of lime is laid upon the wall Although it is a less demanding technique the resulting painting is more pastel or chalky and not as durable as Buon fresco Often called Fresco secco or Mezzo-fresco (See Note below)