Le patine bianche sui dipinti delle tombe di Tarquinia: il moonmilk

The Etruscan tombs of Tarquinia hold a treasure, not visible to the naked eye, formed by a microbial community unique in the world. Over the centuries, microorganisms have produced a white patina that has covered the surfaces of these hypogeal environments. In some tombs this patina appears as a veil, while in others the thickness is a few centimeters. Further analysis has recently revealed that this patina is formed by a peculiar structure of calcium carbonate, called Moonmilk. The Moonmilk was formed over the centuries thanks to the metabolism of microorganisms and to specific environmental conditions. This article traces the history of the discovery of Moonmilk in the tombs of Tarquinia and presents a unique example of biocolonization that contributes to the protection of wall paintings and not to their degradation.