It’s not so much the shimmering beauty of natural pearls that made them more valuable than diamonds during the Gilded Age, but rather the danger inherent in the task of finding the perfect pearl. The divers plunged deep into the waters in search of the gems—alas, most of the mollusks were empty or the pearls found inside them were ill-shaped. It took years for Pierre Cartier, a French jeweler, to acquire the finest gems to create an extraordinary pearl necklace. This leads us to the story of the Cartier Building—a tale that starts with the house of Morton F. Plant.

The Morton Plant Mansion

Morton F. Plant—financier, steamship line owner, philanthropist, and sporting man—belonged to society’s most privileged set. Not surprisingly, he chose to reside on Millionaire’s Row—the stretch of Fifth Avenue between 50th and 59th Streets lined with palatial homes of the Gilded Age’s super wealthy.

The Morton Plant House was located at 653 Fifth Avenue, the corner meeting 52nd Street. The lot for the house, bought from the Vanderbilts, faced the Triple Palace—the imposing home of William H. Vanderbilt and his two daughters.

Designed by Robert W. Gibson in 1905, 653 Fifth Avenue was to be Plant’s permanent residence—but destiny had its own plan. A few years after the house was built, the relentless match of commerce started changing the face of Fifth Avenue. The rapid influx of hotels and stores into the area pushed the exclusive mansions further uptown. Reluctant to part with his residence, Morton Plant found himself increasingly isolated from his peer group.

At the same time, Plant’s personal life took a dramatic turn. After the death of his first wife of many years, the 61-year-old Plant fell in love with Mae Caldwell Manwaring, or “Maisie”—30 years his junior. The pair got married in 1914 and settled in Plant’s Fifth Avenue mansion.

Cartier Mansion Barter

A French jeweler named Pierre Cartier, who arrived in New York in 1909, happened to be searching for a mansion worthy of housing Cartier’s exquisite jewels and matching the elegance of Cartier’s flagship store in Paris. Cartier had his eye set on the most elegant of the Fifth Avenue mansions: Morton Plant’s beautiful home. All his advances were rebuffed until the young Mrs. Plant set her beautiful eyes on one of the jeweler’s rare pearl necklaces. Cartier’s drive to possess the house coupled with Mrs. Plant’s desire to wrap the piece of jewelry around her graceful neck resulted in a most unusual real estate agreement: the mansion was bartered to Cartier for a million-dollar string of pearls. To be fair, it was not just a string, but a double-string made of the most perfect, exquisite Cartier pearls.

Missing pearls and 5th Avenue Cartier’s flagship store

The sale took place in 1917. Mr. and Mrs. Morton Plant moved to their new mansion up Fifth Ave—a prime new location for exclusive private residences. Morton Plant died the next year, while Mrs. Plant lived as a wealthy widow until she remarried. After her pearl necklace was auctioned in the 1950s, it was never seen again.

The beautiful Plant mansion still stands as Cartier’s flagship store. One of the very few Gilded Age mansions still standing today, it was ironically saved by the commercial forces that the original owner had so passionately resisted.