Mercury released from the red pigment in Adoration of the Magi (Peter Paul Rubens, 1624) has formed black stains in some places. *Image source: KONINKLIJK MUSEUM VOOR SCHONE KUNSTEN, ANTWERP/GIRAUDON/THE BRIDGEMAN ART LIBRARY    For several centuries, the pigment vermilion has been a favorite of artists, however, it is notorious for turning […]