The Arcot diamonds are again set on the special coronation crown for Queen Adelaide in 1831 but dismounted with other diamonds soon after the coronation 

George IV, who died on June 26, 1830, without legitimate issue, was succeeded by his younger brother William, who ascended the throne as William IV. He inherited the throne when he was 64 years old. Prince William married Princess Adelaide of Saxe-Meningen, who was 27 years younger to him, in 1818. The couple could not produce an issue that survived into aulthood, as Princess Adelaide's pregnancies either ended in miscarriages or the children born would not survive into adulthood. When Prince William ascended the throne as king, Princess Adelaide became the Queen consort of the United Kingdom and Hanover. 

The coronation of William IV was held on September 8, 1831. In view of this coronation, it was thought that the Crown of Mary of Modena, first made for the wife of King James II, and traditionally used for the crowning of Queen consorts of England and the United Kingdom, was unfit for the coronation of Queen Adelaide, and the court jewelers were commissioned to create a new coronation crown for the Queen, that came to be known as the "Crown of Queen Adelaide." The design of the crown was based on the traditional British model, with four half-arches meeting a globe or monde, on top of which sat a cross. The Queen who objected to the standard practice of hiring diamonds and other jewels for the designing of crowns, provided diamonds from her own private jewelry to be installed on the crown. However, the Arcot diamonds which were now unmounted and in the custody of the Crown Jewelers were again used, perhaps with the permission of the Queen, to supplement her own diamonds. A large pear-shaped diamond was mounted on the four trefoils of the crown, as seen on the lithograph of the crown. Out of these four pear-shaped diamonds, two are undoubtedly the Arcot diamonds, if the report about the use of the Arcot diamonds on the crown is correct. Soon after the coronation in September 1831, the diamonds were all removed and the Crown of Queen Adelaide was stored as a shell. Queen Adelaide set the precedent for the creation and use of special consort crowns for the coronation, which was followed by other British Queen Consorts after her, such as Alexandra of Denmark in 1902, Mary of Teck in 1911, and Elizabeth Bowes-Lyon in 1937. The Arcot diamonds of Queen Charlotte was once again unmounted, and remained in the custody of the Crown Jewelers.