Kate was gifted this poppy/anemone brooch by the wife of Ben Roberts-Smith, a recipient of the Victoria Cross. It is not actually a poppy, but an reproduction of an anemone created by Fabergé. The Metropolitan Museum of Art in New York has a copy of the reproduction for sale and describes it:
"Among the exquisite works produced in Peter Carl Fabergé’s (Russian, 1846–1920) studios is the Imperial Anemones (19th–20th century), a fanciful creation featuring a “bouquet” of gold, enamel, and jade blossoms gathered in a rock crystal vase. This sumptuous Fabergé object was owned until 1918 by the Dowager Empress Maria Feodorovna. Now in The Matilda Geddings Gray Foundation Collection, it is on long- term loan to The Metropolitan Museum of Art and is the basis for our whimsical necklace."
ID Credit: Ayvee at Diana's Jewels