An Art Deco rock crystal brooch, circa 1920, the barrel-shaped polished rock crystal with openwork geometric terminals, set throughout with single and rose-cut diamonds, with baton-shaped onyx cabochons, mounted in platinum and gold, French assay marks, partial maker’s mark, cased by Van Cleef & Arpels, length 6cm. £2,000-£3,000

Sotheby’s, The Duchess; Precious Objects and Property from the Estate of Mary, Duchess of Roxburghe, 27 May 2015, lot 660.

Literature:
Anon, Lady Crewe’s Jewels – Worn Constantly, 22 July 1933, p.8, ‘Crystal Brooch, long with diamond and onyx ornament at each end’.