A: Milano, Lombardia, Italy, B: Firenze, Toscana, Italy, C: Brooklyn, New York, United States
In April 2006 Carmen Bambach of the Metropolitan Museum of Art, New York discovered an extensive invasion of molds of various colors, "including black, red, and purple, along with swelling of pages" on the priceless manuscripts of Leonardo da Vinci's Codex Atlanticus, preserved in the Bibliotheca Ambrosiana in Milan.
In 2008 The Opificio delle Pietre Dure, in Florence "determined that the colors found on the pages weren't the product of mold, but instead caused by mercury salts added to protect the Codex from mold."