A public preview will be staged starting from May 24.

One of the auction’s highlights is a set of 60 fancy coloured diamonds from a European private collection. All the stones in the collection are certified, Tiancheng said.

A 21.91-carat Type IIa Triple Excellent (excellent in cut, polish and symmetry) D flawless unmounted brilliant-cut round diamond, with an estimated price of $5.1 million (HK$39.5 million) to $5.4 million (HK$41.5 million), will also go under the hammer.

A pair of ruby and diamond earrings from the house of Bulgari is also expected to draw a lot of interest from collectors. Each oval-shaped ruby weighs 7.70 carats and 6.82 carats respectively, complemented by round and marquise-shaped diamonds.

Large, translucent jadeite beads that used to adorn emperors and high court officials are exceedingly rare today. Tiancheng is delighted to offer a jadeite bead necklace, which is estimated to fetch $7.6 million (HK$59 million) to $10.3 million (HK$80 million). The piece is composed of 23 bright green beads measuring approximately 16.61mm to 21.54mm.

Complementing a traditional jadeite bead necklace is another classic favourite form of jadeite jewellery: bangle. On offer is a jadeite bangle, which is expected to command $580,000 (HK$4.5 million) to $876,500 (HK$6.8 million). The bangle features bright green patches that resemble the marbling effect that one sees on Chinese ink paintings.

In addition to these classic Chinese designs for jadeite is a black jadeite and diamond pendant created by Alessio Boschi.  Estimated to fetch $71,000 (HK$550,000) to $90,000 (HK$700,000), the rectangular jadeite plaque exhibits a nearly black colour but gleams an enticing dark green colour when placed under bright light.