One of the most controversial art works of the 1990s is going up for auction, and it could be yours – elephant dung and all – for around $2.3 million. “The Holy Virgin Mary,” a 1996 painting by British artist Chris Ofili, created a firestorm of controversy when it was exhibited at the Brooklyn Museum of Art in 1999. The painting depicts a black Madonna figure baring one breast, which is made from lacquered elephant dung and surrounded by butterfly-like formations of female genitalia (a play on the term putti, a type of cherub depicted in religious art). Many Catholics...