Londonderry Emerald Necklace & Earrings. Marquise daughter Amelia, Castle Ray Vicomtesse (1762-1829), then of her nephew from (died 1817) and his widow Caroline (1723-1793) 2nd Earl of Buckinghamshire, 7th Marquess to Rotian (1794-1844), which was hereditary and family to then current.
The Londonderry Tiara (top) worn by Theresa. A much revised version of the tiara worn by the Marchioness of Londonderry to the Devonshire House Ball of 1897. Also worn at the coronation of Edward VII in 1902. On that occasion she accidentally dropped into the toliet. It was retrieved with great difficulty. Previous versions had a pearl set in each element instead of diamonds.