One of the only round large pink diamonds known to be in existence will be auctioned off at Christie's Hong Kong Magnificent Jewels sale on May 29, Forbes reported. The gem is expected to sell for between $8 and $10 million and will be offered alongside an additional round diamond, a potentially flawless 11.85-carat gem.
The ultra-rare pink diamond was dubbed the "Martian Pink" as it was purchased from Harry Winston in 1976, the same year that the United States landed a spacecraft on Martian soil. Diamonds that naturally exude a pinkish hue often contain a purple, orange or grey color modifier, but the Martian Pink contains no such color modifier, Christie's said, augmenting its significance.
The only other pink diamond of significant size is the 23.6-carat Williamson Pink which was gifted to the British Queen Elizabeth II in 1947 on the occasion of her wedding, Forbes reported.