How much would a 40 carat emerald cut canary diamond cost?

This rare stone may be available at an auction, but it is unusual enough that there are probably very few stones that meet this description.

One commercially available yellow stone for sale today on Blue diamond -- the largest yellow -- is a 7.37-Carat Fancy Light Yellow Radiant-Cut Diamond priced at $84,966.

(Jackie Onassis was given a 40-carat diamond when she became engaged to Onassis. It was auctioned in 1996 for US$2,500,000. A yellow diamond of this size would certainly cost perhaps millions more.)