I recently finished a book called Diamond: A Journey to the Heart of an Obsession by Matthew Hart which explores the history of the diamond trade. The book begins with the discovery of a large pink diamond in Brazil. There's something distinctly alluring about the big pink diamonds. A few years ago, pink diamonds loomed large in the public consciousness after Ben Affleck bestowed a bubblegum pink, six carat diamond on Jennifer Lopez.

Since then prices for pink diamonds have varied. The Economist covers the history of the 28-carat pink available for bid at Sotheby's Magnificent Jewels auction on December 6. We first heard of this gem back in May 2005 when it failed to sell at auction. The sparkler was on its own then, now it has been mounted into a ring to better tempt those who might slide this cotton-candy confection onto a finger and decide they must possess it at all costs. Young women in Hong Kong and China have pushing up the prices of these stones. This diamond could sell for over $7 million even though it is graded VS2 (a trained eye and a 10x loupe could spot the flaws).

The gem was found in either Britain or Angola and may well be the big pink diamond of Hart's book (the rough diamond was sold and Hart never saw it after it was polished). I suspect this diamond won't go unsold this time, after all a paler and slightly smaller pink sold for a similar price in 2005.