Tiffany & Co. is the jewelry brand most widely purchased by ultrawealthy women, according to a study by The Luxury Institute.

The institute surveyed ultrawealthy U.S. consumers with minimum net worth of $5 million about luxury brands they buy and the relationships they have with luxury sales professionals.

David Yurman and Cartier followed Tiffany on the list. The women surveyed said they have a preferred salesperson at all three jewelers. And never underestimate the power of the pen: ?More than half of ultrawealthy women who purchase from both jewelry and fashion brands say they appreciate handwritten thank-you notes. ?

“Relationship selling is not something exclusive to markets like high-end automobiles, real estate and wealth management services,” said Luxury Institute CEO Milton Pedraza in a statement. “Even in luxury jewelry and fashion, relationships cultivated by trust and an understanding of customer preferences can help boost both the frequency and size of sales.”

JCK