(1 Apr 2011) 1. Emerald and diamond tiara 2. Pan Colombian emerald pear-shaped drops 3. Tilt up diamonds to emerald pear-shaped drops 4. Alexandra Rhodes, senior international jewelry specialist of Sotheby's, taking the tiara from the display cabinet 5. Alexandra Rhodes, senior international jewelry specialist of Sotheby's, putting the tiara onto the display case 6. Close up of the diamonds of the tiara 7. SOUNDBITE (English) Alexandra Rhodes, senior international jewelry specialist of Sotheby's: "As you can see with emeralds you need this consistency of colours, this wonderful grass green, very bright and vibrant colour. And in themselves, the way they are matched, and the size is....extraordinary. Equally the diamonds, you've got these fantastic cushion shape, a slight tint of yellow colour but beautifully made, equally the setting is the garland style, the turn of the 19th century into the 20th century, very light and very feminine form of jewel. All in all, the make and the stones, the workmanship is fabulous." 8. Tiara on the display case 9. Wide shot, photo of Princess Katherina next to the tiara STORYLINE: A rare emerald and diamond tiara went on display in Hong Kong on Friday before it is put under hammer later in Geneva. The tiara is composed of 11 Colombian emerald pear-shaped drops which weigh over 500 carats in total. It is believed that the tiara was commissioned sometime during 1900, possibly from the renowned French jewellers Chaumet, by Guido, Count von Henkel, First Prince von Donnersmarck, for his second wife Princess Katharina. It may well have been one of the most precious pieces in the collection of the Donnersmarcks. The family's jewelry collection was known to be on a par with, or even to have exceeded, those of many of the crowned heads of Europe. Alexandra Rhodes, senior international jewelry specialist of auctioneers Sotheby's, said the workmanship of the tiara was "fabulous". It is estimated the tiara will fetch around 5 -10 (m) million US dollars (3.1 (m) - �6.2 (m) million pounds) in the auction to be held in Geneva on 17 May this year. Find out more about AP Archive: http://www.aparchive.com/HowWeWork Twitter: https://twitter.com/AP_Archive Facebook: https://www.facebook.com/APArchives Instagram: https://www.instagram.com/APNews/ You can license this story through AP Archive: http://www.aparchive.com/metadata/youtube/75124919e571a37efffd0bdc5d8d10f2