On March 1, 1988, De Beers was having a big bash to celebrate their 100 years in business. Chairman Julian Oglivie capped off his speech with a little tidbit that stunned the crowd – De Beers’ Premier Mine had recently uncovered a diamond that was perfect in color and weighed 599 carats. It had been found nearly two years before; the company kept it quiet for the sole purpose of flaunting it at their 100th anniversary. It didn’t get to keep all 599 of those carats, though – it had to be cut down to remove some cracks around the edges and it took 154 days to cut 50 carats away. That was just the beginning of the stone’s overhaul – when all was said and done, the Centenary ended up weighing 273.85 carats with 247 facets. It was on loan to the Tower of London for a number of years (have any of you seen it?), but it’s rumored that the stone has since been sold. De Beers remains mum on the subject, saying they respect their clients’ anonymity.