Marie Feodorovna's Wave necklace, probably, by Cartier. It is often said this necklace could be converted into a tiara but actually this necklace and tiara were definitely two separate jewels. In the famous photograph made by the Soviets for inventory purposes both the tiara and the necklace appear. A brooch, necklace and tiara formed a parure, which today's existence is under the question.
"Love Brooch" first documented in the inventory of Emperor Ferdinand I (1793-1875), Emperor or Austria, President of the German Confederation, King of Hungary and Bohemia | It probably came into Habsburg possession through his grandmother, Archduchess Mary of Burgundy in the fifteenth century.
Close up of tiara from the Queen of Sheba Parure - large honey-coloured diamonds, white brilliant-cut diamonds, smaller honey-coloured diamonds, rose-cut and old-cut diamonds set in yellow and white gold (some of which has been oxidized). It was designed specially for Lady Colin Campbell. The parure consists of a tiara, necklace, long-drop earrings, ring and bracelet.