The World’s Largest Diamond | Matthew Hart | Vanity Fair | 8th August 2016

Diamond pricing is an “arcane, rapacious art”. The per-carat price of diamonds rises exponentially with size. A top-color, best-cut white weighing a single carat runs about $30,000. A 100-carat stone of the same quality sold at Sotheby’s in New York last year for $22 million — $220,000 per carat. But a diamond weighing more than a thousand carats? “The stock market flailed around for a value. Clearly there was no easy way to fix a price, but everyone knew it would be a lot”