This elaborate brooch was part of the wedding gifts Queen Elizabeth the Queen Mother received from her husband.
Unlike the necklace, QEQM never changed the brooch and it became a life long favourite.
Hugh Roberts in The Queen's Diamonds calls it the Duchess of Teck flower brooch and suggests that the brooch may have been one which Princess Mary, Duchess of Gloucester, left to Princess Mary Adelaide. I can understand Roberts' lack of certainty as to whether it originally belonged to Princess Mary as her will describes a "square" brooch with pendants.
According to Roberts, after Princess Mary Adelaide's death, the brooch was given to Prince Adolphus, her eldest son, but by 1923 it was in Queen Mary's possession.
QEQM wore it for day time events, as well as grand evening functions.
HM in Paris for the 1938 State visit.