Four of Princess Alice’s surviving children and their spouses gave their grandmother a magnificent diamond and sapphire brooch.
The Emperor and Empress of Russia, the Grand Duke and Duchess of Hesse, the Grand Duchess Elizabeth Feodorovna “Ella” and the Grand Duke Serge along with Princess Victoria and Prince Louis of Battenberg’s gift was “…a brooch with an open pendant heart of diamonds, bearing in the centre the number "60" in Slavonic characters. It has on the top a cabochon sapphire and there are two large sapphire drops.” The jeweller created this jewel was the workshops of Fabergé(the see note from Empress Alexandra about the payment).
Queen Victoria left it to her third daughter Princess Helena. It has since returned to the Royal Collection.
The brooch disappeared into the vaults not to be seen in public until the 21st century. The Duchess of Cornwall has been seen wearing the brooch on several occasions, including Remembrance Sunday and in Philadelphia.
Victoria's 1897 Diamond Jubilee was marked by nationwide celebrations and local festivities. It was a gathering of her large family but she didn't invite everyone as she had 10 years before; she decreed that no other reigning monarchs should attend since she was just too old.
Queen Victoria's Diamond Jubilee Family Dinner Party was held at Buckingham Palace on 21 June 1897. The Queen wore a dress, made in India, with the whole front embroidered in gold. She was looking quite as grand as she could in her unfashionable silks and satins, widowscap with diamonds and diamond necklace.
Sources: The Illustrated London News; The New York Times; T he Graphic, The Times
Thank you Laura for your help.