A late 19th century fringe necklace converting to a tiara

A late 19th century fringe necklace converting to a tiara, the line of thirty seven old cushion-shaped diamonds alternately suspend a trefoil of diamonds and a diamond drop, each with two graduated old circular-cut diamonds in silver and gold. On a detachable pierced knife-edge chain, each section set with a rose-cut diamond. With stamped inventory number 19926. In fitted case by Cartier. The box contains the original fitting so that the fringe section can we worn as a tiara.

With purchase invoice from Cartier from July 4th 1960 for £900.