A pale, greenish-yellow non-drying oil expressed from the fruit of the olive tree, Olea europaea. Olive oil contains glycerides of oleic acid (56-83%), palmitic acid (8-18%), linoleic acid (4-19%), stearic acid (2-5%), linolenic acid (0.3-1%) and arachidic acid (0.9%) with small amounts of squalene, phytosterol and tocopherol (Serpico and White 2000). Olive oil becomes rancid on exposure to air and becomes turbid at cold temperatures. The application of oil, including olive oil, to the surface of stucco marble has always been quite common in order to increase the gloss of an already well polished surface. Wittenburg (1999); Serpico and White (2000); Museum of Fine Arts, Boston (2000). [J. Cassar, R. de Angelis]