Prices for the rarest stones from Rio Tinto’s defunct Australian mine have long outperformed mainstream investments ...

Composed of approximately 300 carats of old mine-cut diamonds, the historic piece was once worn during royal coronations and ...

A remarkably rare 18th-century diamond necklace ... weighing approximately 300 carats and composed of around 500 old mine brilliant-cut diamonds, was showcased in Sotheby’s 'Royal and Noble ...