The lunar rocks, recovered by the USSR in the '70s, are the only known documented samples in private hands, according to Sotheby's.
The street artist's prank at Sotheby's lit a trick candle in a musty room. But in rebelling against the monied art establishment, he still profits.
The total value is estimated at up to $2.8 million.
A 1980s flea market find turns out to be a 26-carat diamond.
For decades, the owner thought it was just a fun piece of costume jewelry.