An Edwardian diamond tiara converting to a necklace

An Edwardian diamond tiara converting to a necklace, mounted with a line of slightly graduated old circular-cut diamonds, alternately suspending a further line of old circular-cut diamonds and foliate drops set with further graduated old circular-cut diamonds. With knife-edge back chain set with small circular-cut diamonds. Set in white gold and platinum. With tiara frame concealed in fitted box by Collingwood.