The Christie's Geneva auction sold the 76.02 carats, D / IF Cushion cut Archduke Joseph Diamond sourced from the Golconda mines in India, for a value of $21,474,525, which it noted is a world record for a Golconda diamond and a world record price per carat for a colourless diamond, reports say.
The diamond is characterized as colourless, internally flawless, reports suggest.
The auction sold 19 lots over $1 million each, reports say.
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