A 54-pound (25-kilogram) rock. Estimated auction price: $2 million to $4 million. Why so expensive? It's the largest piece of ...

The auction house Sotheby’s has offered a new way to get a piece of Mars without entrusting your life to Elon Musk, who has pledged to send people to Mars by 2029: Buying a piece of it instead. A ...

Grande tête mince” — a bronze sculpture by Alberto Giacometti — failed to meet expectations at a recent Sotheby’s auction.