A diamond necklace, by Harry Winston. Estimate CHF800,000 – CHF1,200,000 ($805,839 - $1,208,759). Photo Christie's Image Ltd 2015

Designed as a flexible graduated wreath, centering five marquise-cut diamonds, weighing approximately 7.15, 5.01, 4.01, 2.75 and 2.42 carats, to the marquise, pear and round brilliant-cut diamond double row, the front section can be detached to form a bracelet, 2000, necklace 38.0 cm, bracelet 17.8 cm, mounted in platinum and gold, in blue leather Harry Winston case. Signed HW for Harry Winston, no.64483 

Accompanied by report no. 5172236784 dated 16 July 2015 from the GIA Gemological Institute of America stating that the 7.15 carat diamond is G colour, VS2 clarity.
Report no. 1176236766 dated 17 July 2015 from the GIA Gemological Institute of America stating that the 5.01 carat diamond is E colour, VS1 clarity.
Report no. 6173236771 dated 16 July 2015 from the GIA Gemological Institute of America stating that the 4.01 carat diamond is G colour, VS1 clarity.
Report no. 2173236753 dated 17 July 2015 from the GIA Gemological Institute of America stating that the 2.75 carat diamond is F colour, SI1 clarity.
Report no. 1172236776 dated 17 July 2015 from the GIA Gemological Institute of America stating that the 2.42 carat diamond is F colour, VVS2 clarity.
And 31 reports dated 2001 to 1990 from the GIA Gemological Institute of America. 

Christie's. GENEVA MAGNIFICENT JEWELS, 10 November 2015, Geneva