Mark Rothko, a master of Abstract Expressionism, is known to have created 835 paintings during the course of his five-decade career. Christie's claims it just found No. 836.
Christie's expects to sell Mark Rothko's 'Untitled #17,' dating to 1961, for at least $18 million next month.
The auction house said it has discovered a previously unknown Rothko painting, which it expects to sell for at least $18 million on May 11 in New York.