An impressive diamond necklace, by Cartier, circa 1955

The lattice bib of brilliant and square-cut diamonds, suspending a graduating fringe of pear-shaped diamond drops, each within an openwork brilliant-cut diamond lozenge, diamonds approximately 100.00 carats total, signed Cartier Paris, numbers partially indistinct, maker's marks, French assay marks, length 36.0cm. Sold for £520,000 plus Premium and tax

Note : The three largest pear-shaped diamonds each accompanied by certificates from the GIA stating that the diamond weighing 5.56 carats is D colour VS2 clarity, the diamond weighing 6.98 carats is D colour Si1 clarity and the diamond weighing 4.35 carats is D colour Vs clarity. Certificate numbers 15724280, 15724284, 15724286, dated 22nd February 2007.

This spectacular diamond necklace by Cartier, circa 1955, perfectly encapsulates the flamboyance of the post-war period when fashion turned its back on the austerity and deprivations of the war years. Set with approximately one hundred carats of diamonds, the fringe of diamond drops is designed to sit on the collarbone and would have perfectly complemented the glamorous `New Look` evening gowns of the 1950s, which were draped in luxurious fabrics, with low décolletés and tightly corseted waists.

It formed part of the collection of Anne Moen Bullitt, a wealthy beauty whose wardrobe, once described as “an amazing collection from the golden age of couture”, perfectly matched her society lifestyle.

Anne’s father was William Christian Bullitt, the American millionaire diplomat, journalist and novelist. Her mother, who died when she was eight, was Louise Bryant, an American journalist and radical who counted Eugene O’Neill and F. Scott Fitzgerald as friends and who was part of the Parisian ex-patriot set of the 1920s.

Louise Bryant witnessed first hand the Bolshevik Revolution in Moscow with her first husband, John Reed. Their tempestuous relationship was the basis for the 1981, Oscar-winning film “Reds”, with Reed played by Warren Beatty and Bryant by Diane Keating.

After Reed’s death in 1920, Bryant remained in Europe as a leading correspondent for the Hearst newspaper chain; she interviewed Kemal Ataturk, founder of the Turkish Republic and Mussolini gave his first interview with a news correspondent to her. Around this time she met Bill Bullitt and the couple later married in Paris in 1923. In 1924 Anne was born. By 1928 their marriage was floundering, partly due to Louise’s contraction of an incurable and painful skin condition, which led to her reliance on alcohol, which in turn led to bouts of depression and paranoia. The couple divorced in 1930 and Bullitt retained sole custody of Anne.

During the 1930s, `Little Anne Bullitt` as the press often dubbed her, was her father’s companion and aide during his travels and foreign assignments as Ambassador to the Soviet Union and France under President Franklin D. Roosevelt. Anne treasured the memories and her meetings with foreign dignitaries and heads of state. During one of her visits to Hyde Park when she was twelve, Roosevelt, expecting a delegation of local politicians, told her to hide behind the sofa in his study so she could overhear their conversation.

After the war, she bought the 700 acre Palmerston estate in, County Kildare, Ireland and for the next forty years this provided the setting for her distinguished racing career, in which she became the first female breeder and trainer of thoroughbred horses in Ireland and Palmerston Stud became the largest horse farm.

But perhaps her greatest legacy was her meticulously catalogued collection of her famous parents’ writings, which have subsequently been presented to Yale University. Amongst these papers are unpublished poems by Eugene O’Neill, Louise Bryant’s notes for unpublished articles, her address books with numbers and addresses for Lenin, Trotsky, Marcel Duchamp, Anita Loos, Brancusi and Helen Keller, to name but a few, and manuscripts by Sigmund Freud – a friend of Bill Bullitt’s, by whom he was psychoanalysed in the 1920s.

Anne Bullitt died in Dublin in August 2007 after a long illness. Although married four times, to Caspar Wistar Barton Townsend Jr, Nicholas Duke Biddle, Roderic More O’Ferrall and Daniel B. Brewster, she is buried according to her wish, alongside her beloved father in Philadelphia. Once, when asked by Freud if she loved her father, a young Anne replied, “My father is God”. Dr Freud said, “That child is very articulate. You know I have developed a theory that male children’s first love is their mother and females’ their father. But this is the first time a child had confirmed my theory”.

Bonhams. Fine Jewellery. 6 December 2007. New Bond Street.