Crowns and jewels that gave Callas extra sparkle

He went on to produce dozens more pieces for her for more than a decade to come, often on the basis of sketches by directors such as Franco Zeffirelli and Luchino Visconti or famous costume designers such as Lila de Nobili. Now an exhibition of the pieces that brought extra sparkle to Callas's celebrated singing have gone on show at the Royal Opera House in London, where she gave her final stage performance as Tosca 40 years ago.

The free exhibition at Covent Garden includes 60 pieces of jewellery presented with some of the costumes she wore with them and programmes and photographs of the time.

The show includes one set of jewellery rediscovered by its curator, Rinaldo Albanesi. It was considered impossible to identify for which opera the diadem and matching necklace and earrings were created but Simonetta Puccini, granddaughter of the composer Giacomo Puccini, and Franca Cella, a researcher, recognised them as having been made for her performance in Tosca with the Metropolitan Opera in New York in 1956.

Other pieces include a crown worn by Callas for Nabucco in Naples in 1949, a role she never sang again, and the laurel wreath crown from Norma, which she performed in Chicago in 1954 as part of her American debut.

Other pieces, made for a performance of La Traviata at La Scala a year later, are accurate reproductions of period jewellery insisted upon by the director, Visconti.

Callas loved many of the pieces so much that she would sometimes combine her stage jewellery with the gems presented to her after each premiere by her husband, the businessman Giovanni Battista Meneghini, whom she was eventually to leave for the tycoon Aristotle Onassis.

When Callas - who was born in New York's Greek immigrant quarter in 1923 - died in 1977, ownership of the stage pieces created for her by Marangoni reverted to his workshop. The Swarovski company, which supplied crystals, bought the Atelier Marangoni when it was put up for sale in 1999, thereby preventing the dispersal of the Callas archive around the world.

Some of the pieces are now half a century old and they have undergone restoration for this exhibition, which will continue at Covent Garden until 10 January before travelling to Prague, Brussels and New York. It has already been seen in Vienna, Florence, Salzburg and Monte Carlo.

Dr Albanesi, of Swarovski events, said the company was "bringing an old dream back to life - the dream of extravagant opera productions and the dream of the greatest soprano of all times, the divine Maria Callas".