Editor’s Note
This article describes the remarkable auction of Lady Glenconner’s antique diamond tiara, which sold for more than double its pre-sale estimate. The piece carries significant royal provenance, having been worn for major state and ceremonial occasions.

LONDON — Lady Glenconner’s antique diamond tiara, with its glittering starburst designs, fetched £127,400, more than double its estimate, at Bonhams London Jewels sale on Thursday night.
Anne Glenconner, the British aristocrat, author and former lady-in-waiting to Princess Margaret, had worn the tiara, which dates to around 1880, for state banquets, royal tours and for a portrait taken in 1983 with other maids of honour from the coronation of Queen Elizabeth II.
Glenconner famously spent more than three decades as lady-in-waiting — or hardworking personal assistant — for her childhood friend Princess Margaret. A mother of five, she also served as hostess-in-chief on the Caribbean island of Mustique, which her late husband Colin Tennant, 3rd Baron Glenconner, purchased, and turned into a royal and celebrity playground.
The tiara was part of a 20-lot sale of her colorful jewels that raised a total of £256,065. Bonhams said the entire collection sold on the night.

In an interview last month, Glenconner said she plans to give the proceeds of the sale to her children and set up a trust for her son Christopher Tennant, who was brain-damaged in a motorcycle accident in Belize in the 1980s.
The tiara comprises eight diamond stars, with the principal diamond at the center of the largest star weighing approximately 3.5 carats. The remaining cushion and old brilliant-cut diamonds weigh approximately 75 carats in total. The piece can be worn as either a tiara with seven stars, or as a coronet with all eight stars. Each diamond star can also be worn as an individual brooch.
Many of Lady Glenconner’s other jewels in the sale had hefty names attached, including Cartier, Verdura, Andrew Grima and David Webb, but even the ones that were not branded told rich stories about the 93-year-old, whose charmed life has been spiked with tragedy.
Glenconner’s jewels weren’t the only aristocratic rocks on the Bonhams block. A diamond bracelet, circa 1870, from the collection of Nancy Astor, Viscountess Astor, appeared on the market for the first time, and sold for £95,650, more than three times its pre-sale estimate.
The bracelet has a design of circlets and ivy leaves and is set with old brilliant and rose-cut diamonds, with an approximate weight of 36 carats.

As reported, Nancy Astor’s turquoise and diamond Cartier tiara outstripped expectations, selling for £889,400, three times the asking price, at Bonhams London Jewels sale in June.
The bandeau tiara, with its carved turquoise plumes, leaves and scrolls, is a rare piece and was on the market for the first time since Nancy’s husband Lord Astor purchased it from Cartier in 1930. It had been put up for sale by one of Nancy Astor’s heirs.
Nancy Astor was born Nancy Witcher Langhorne in Danville, Va. After marrying her second husband, Waldorf Astor, 2nd Viscount Astor, she settled in the U.K. She later became the first woman to take her seat in Parliament, serving from 1919 to 1945 and advocating for temperance, welfare, education reform and women’s rights.
The top lot at Bonhams auction on Thursday was a Colombian diamond and emerald ring that sold for £597,300, more than eight times its estimate. The step-cut emerald weighs 10.37 carats, and is set within a surround of marquise and brilliant-cut diamonds.

Jennifer Tonkin, Bonhams co-head of department, jewelry, U.K., commented on the sale results.