A reassessment of the formation of the patina called<i>scialbatura</i>

Abstract

AbstractThe nature and the origin of the patina upon stone has been investigated. The formation of oxalate scialbatura on marbles and limestones is not always related to the metabolic activity of lichens. Two cases are discussed: an example of an oxalate patina formed by an old protective treatment, presumably with calcium caseinate, and an example of a patina without oxalates. A case is also given where both lichens and oxalates have been found on a stone surface but a patina did not form.