the central section of her Sautoir/longchain does look like it but why would Marchioness Curzon wear costume jewellery.
I’d found it much more surprising if it turned out that the Vicereine of India had worn costume jewellery for the most important social event during her husband’s tenure.
Mary Curzon’s last will, drawn up during her passage to India in 1898, made provisions for the major pieces of jewellery in her possession. Yet, it didn’t mention a necklace with coloured gemstones like the one she was wearing with her Boucheron tiara and Watherston diamond necklace for the state ball during the Delhi Durbar.
While many contemporary reports mistook the iridescent beetlewings in Mary Curzon’s famous evening gown for emeralds, I don’t think the photos depict her wearing an emerald necklace. In a previous post about her jewels I speculated the gemstones could be amethysts, but of course, that’s just a speculation, based on what might have been considered a suitable complement to the gold-embroidered peacock dress.
Now a faux sapphire (paste) necklace was somewhat surprising, but it would at least explain why it wasn’t mentioned in her will.
Regarding Grace, Marchioness Curzon of Kedleston possibly wearing the same necklace as the lower section of her sautoir: I count 13 clusters set in a slightly different way and closer to each other than the upper part of the sautoir, which I believe could be the ornaments Mary Curzon wore on her shoulders, lining her dress for the Delhi Durbar.
In any case, it is known that Lord Curzon disregarded his first wife’s will and gave her jewels to his second wife, to such an extent, that his youngest daughter had to acquire a new tiara for her wedding.
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