Madonna Pietra degli Scrovigni
Marie Spartali Stillman (1844-1927)
Watercolour and bodycolour
Collection: Walker Gallery, Liverpool
Source: Wikimedia Commons
Depicting the cold, heartless woman of Dante's poem of the same title ("Utterly frozen ... no more moved than is the stone"), this still manages to be alluring. [Commentary continues below.]
Image download and commentary by Jacqueline Banerjee. [Click on the image to enlarge it, and mouse over the text for links.]
Identified as being in the public domain.