How Cartier's New York store was swapped for Maisie Plant's pearl necklace

In 1916, the Cartier family was building their reputation in New York by offering the world's finest gems and jewels. A young client named Maisie Plant spotted a double-stranded pearl necklace in Cartier's window, valued at one million dollars. When her husband Morton Plant, a businessman and friend of Pierre Cartier, decided to sell his Fifth Avenue townhouse—also valued at one million dollars—Pierre Cartier proposed an ingenious swap: the necklace for the building.

The trade proved to be one of the best business deals of the century. Pierre Cartier transformed the townhouse into Cartier's New York headquarters, where it remains today. While the value of the pearl necklace remained relatively static over time, the Fifth Avenue property appreciated dramatically, making this exchange a masterstroke of business acumen and a pivotal moment in establishing Cartier's American presence.