Below are some photos from the Beau Geste Party held in December 1938 to raise funds for the British Homeopathic Society for medical research. It was one of the many "Jewel Balls" where leading jewellery firms and private individuals lent jewels which were modelled by society ladies.
Some of the ladies modelling the jewels in 1938.
One of those jewels at the 1938 Beau Geste Party was a large sapphire brooch, said to be the largest in the world. Apart from that, no other identifying details were given.
Mrs Pilkington on the right wearing the sapphire brooch.
The only sapphire brooch which I could identify which might have warranted the description of the largest sapphire brooch in the world is the Logan sapphire, now in the Smithsonian.
https://geogallery.si.edu/10002687/logan-sapphire As this sapphire was owned by Sir Elice Sassoon until circa 1952-3, it might be the brooch in question, but I suspect not as I think that the shape of the stone is different, even allowing for the possibility that the brooch was pinned on an angle.
Has any one any ideas about the sapphire brooch modelled in 1938?