The Internally Flawless 8.41ct Fancy Vivid Purple-Pink Diamond, mined and cut by De Beers from a 19.54ct rough, could become one of the most valuable gems ever sold at auction when it goes under the hammer at Sotheby's Hong Kong this autumn.

The Internally Flawless 8.41ct Fancy Vivid Purple-Pink Diamond, mined and cut by De Beers from a 19.54ct rough, could become one of the most valuable gems ever sold at auction when it goes under the hammer at Sotheby's Hong Kong this autumn.