(IDEX Online) - A Chinese billionaire living in the USA has ordered the world's most expensive COVID-19 face mask - costing $1.5m.Teams of jewelers are working in shifts to set 3,608 natural black and white diamonds (weighing 210 carats) into 270 grams of pure 18k gold.The anonymous customer from Shanghai is having the mask designed and made by Orna and Isaac Levy, owners of the Yvel luxury jewelry brand, in Jerusalem.The buyer has two conditions, insisting it must be ready by the end of 2020, and that it must be the most expensive in the world.The purchase is more costly - and slightly more practical - than that made for Indian businessman Shankar Kurhade, who paid $4,000 for a 50-gram gold mask then said: "I am not sure whether it will be effective." Although the $1.5m mask will be heavy to wear, it incorporates a high-level N99 filter."Every order we receive helps to preserve the company's day-to-day operations," Isaac Levy told The Jerusalem Post newspaper.Pic shows how the finished mask will look, courtesy Yvel