A Belle Époque diamond brooch, circa 1910. Estimate £8,000 - 10,000 (€11,000 - 14,000).  Photo: Bonhams.

The circular plaque of delicate platinum tracery with a central old brilliant-cut diamond framed by horizontal lines of old brilliant and rose-cut diamonds and a similarly-set diamond garland border, accompanied by an associated diamond-set chain, principal diamond approximately 2.00 carats, brooch diameter 5.8cm, necklace length 40.0cm

Bonhams. FINE JEWELLERY, 24 Sep 2015 12:00 BST - LONDON, NEW BOND STREET