Last night the Duchess of Cambridge -- wearing a navy velvet Alexander McQueen gown -- attended a Diplomatic Corps reception at Buckingham Palace. Since the dress code was white tie (read: very fancy) the attire called for tiaras and one's finest jewels. Kate wore Queen Mary's Lover's Knot tiara (a personal favorite of hers) with the Queen's Nizam of Hyderabad necklace and earrings that I believe are also on loan from Her Majesty.