Kate was wearing a bracelet given to her on her visit to Uluru. I believe it is basically decorated gumnuts.
AYERS ROCK, AUSTRALIA - APRIL 22: Catherine, Duchess of Cambridge wears a bracelet she was presented with as she visits an indigenous Training Academy on April 22, 2014 in Ayers Rock, Australia. The Duke and Duchess of Cambridge are on a three-week tour of Australia and New Zealand, the first official trip overseas with their son, Prince George of Cambridge. (Photo by Chris Jackson/Getty Images)