The Duchess of Edinburgh stunned in a diamond and aquamarine tiara as she attended the Buckingham Palace state banquet.Following a packed daytime schedule, the Princess of Wales was absent at the royal dinner.Princess Catherine would have worn a tiara if she had attended the engagement.Sophie, 59, wore a Suzannah dress with the Wessex Aquamarine Necklace Tiara, which is part of the Royal Collection.The Duchess of Edinburgh stunned in a diamond and aquamarine tiaraGettyThe Wessex Aquamarine Necklace Tiara has a wave-like diamond pattern and a seafoam-coloured central aquamarine.It can be converted into a necklace, pendant, or tiara.Sophie, then Countess of Wessex, debuted the dazzling tiara, which has a central stone of a pale green hue, in 2005 for the opera gala held on November 19, Monaco’s National Day.The tiara made a high-profile appearance at Prince Carl Philip and Princess Sofia of Sweden’s wedding in Stockholm in June 2015.The Wessex Aquamarine Necklace Tiara has a wave-like diamond pattern and a seafoam-coloured central aquamarineGettyThe piece was reportedly made for Sophie by Collins & Sons.In March 2006, Sophie wore the tiara in its necklace form at the ChildLine & Mission Enfance Royal gala dinner in London.The Duchess of Edinburgh most recently wore the piece for the first banquet of King Charles since his ascension in November 2022, hosted at Buckingham Palace.Queen Camilla, 77, joined the celebration, dazzling in a Diamond tiara just hours after announcing she was suffering from pneumonia.The tiara made a high-profile appearance at Prince Carl Philip and Princess Sofia of Sweden’s wedding in Stockholm in June 2015GettyHer Highness paid homage to the late Queen Elizabeth with the spectacular diamond piece.King Charles hosted the banquet for the Emir of Qatar, Sheikh Tamim bin Hamad Al Thani and his wife, Sheikha Jawaher bint Hamad bin Suhaim Al Thani during their two-day state visit to the UK.The banquet began with formal speeches by both the King and the Emir, marking the diplomatic significance of the State Visit.The Emir prayed for the King’s health during his speech at Buckingham Palace this evening.