Peter Bradovich's great-grandfather, Metodyj, was one of the most renowned jewelry makers in the Russian empire. In the winter of 1917, Tsar Nicholas's wife, Alexandra, gave him a priceless fifty carat red Peruzzi cut diamond, and six smaller red Mazarin-cut diamonds. Her orders to Metodyj: "Create for me the most magnificent necklace ever seen."On July 16, 1918, the Bolsheviks murdered Nicholas, Alexandra, and their entire family. Metodyj secreted...