The bracelet of the Rainbow is fashioned from 580 emerald-cut sapphires in 30 different colours, 133 baguette-cut rubies set on and around the movement and a1.01 ct. rose-cut diamond for the crown. No price has so been disclosed.

The original Billionaire III watch, launched in 2016, incorporated 656 emerald-cut white diamonds, weighing a total of 129-carats, and cost $3m.

In addition to the new Rainbow edition, New York-based Jacob & Co is also producing the Billionaire III Emeralds with 714 natural emeralds (total 102.35 carats) and the Billionaire III Rubies featuring 714 rubies (147.65 carats).

Last year the company unveiled its $20m Billionaire Timeless Treasure, featuring 216 carats of extremely rare Asscher-cut yellow diamonds.