A.C.C. said:Actually, The Duke and Duchess of Westminster only own 1 Russian tiara and probably a few other pieces. As was said, most of the Romanov jewels now belong to the British Royal Family. Queen Elizabeth II has tons of Russian jewels, due to the purchase of them by Queen Mary, Princess Anne has a few necklaces and chokers from the Romanovs. I also beleive the Duke and Duchess of Gloucester have some pieces.
The Westminster ducal family has a substantial collection of Russian jewels, although not necessarily Romanov jewels. Most of the Romanov jewels remained in Russia, although some were sold after the Revolution by Lenin to raise hard currency. The Dowager Empress Marie had the most substantial collection of all the imperial exiles, followed by Grand Duchess Marie Pavlovna, grandmother to Grand Duchess Helen, the mother of Princess Marina, Duchess of Kent.
While it's true Queen Mary acquired a number of pieces from both the Dowager Empress and Grand Duchess Marie, the majority of their jewels were auctioned off and ended up in the hands of wealthy Americans, including Barbara Hutton, Doris Duke and the Vanderbilts. Some of these pieces were broken up in subsequent sales (the stones are worth far more than the design) and reset by Cartier and Harry Winston for superwealthy clients.