After Thomas Cullinan, the famed South African explorer, bought the Premier Diamond Mine, his workers discovered a nearly flawless 3106.75 carat diamond. "It was the largest rough diamond ever discovered," Post said. Cullinan presented the massive diamond to King Edward VII for his birthday. In honor of his knighthood in 1910, Cullinan created the necklace for his wife, Annie Cullinan. The nine blue diamonds represented the nine pieces that were cut from the original stone. Parts of the huge diamond were placed in the jewelry of the British royal family.
The necklace was given to each first daughter in each generation. "In the early 1980s the great-granddaughter, Anne Robinson, got in touch with Stephen Silver and sold him the heirloom. Then silver sold the necklace to another owner, who is donating it to us," Post explained.