A Spectacular 37.08 carats Diamond Ring

Set with a brilliant-cut diamond weighing 37.08 carats, to the pavé-set diamond gallery and half hoop, mounted in platinum, ring size 5½
Accompanied by original slip and photocopy of report no. 15834096 dated 3 May 2007 from the GIA Gemological Institute of America stating that the diamond is F colour, SI1 clarity, Excellent cut grade, Excellent polish, Excellent symmetry.

Estimate : CHF1,800,000 - CHF2,400,000 ($1,517,347 - $2,023,129)

Notes: The grading of excellent polish, excellent symmetry and excellent cut in such a large diamond is a rare combination.

The finish or surface of diamonds is divided into three categories: polish, symmetry and facet survey. Polish considers any surface characteristics that arise from the finishing process. Symmetry refers to the consistency of the shape, the positioning of the facets and the overall balance of the stone. Facet survey is an overall assessment of the number of facets and general appearance of the stone. That this diamond achieved an excellent/excellent/excellent rating for polish and symmetry shows the diamond cutter's focused skill.

Christie's. Jewels : The Geneva Sale. 20 November 2008. Geneva. Image Christie's Ltd 2008. www.christies.com