Where: Schiphol Airport, Amsterdam
When: Feb. 25, 2005
How much: Possibly $118 million (unconfirmed)
This one makes the list for its sheer dollar amount. Because many of the stolen stones were uncut (and uncut stones are difficult to put a definite value on), an absolute figure has never been confirmed. But if the roughly $118 million estimate is correct, the Amsterdam airport heist is the largest diamond heist ever.
The heist was more like something out of a gangster film than a sophisticated plot like "Ocean's Thirteen" -- it was a truck hijacking, plain and simple. Two weeks before the heist, the thieves did a test run in a stolen KLM Cargo truck. At least one of the thieves broke into the freight area at Schiphol airport and made sure everything was in order. Then on Feb. 25, wearing stolen KLM uniforms and driving yet another stolen KLM truck, the gang drove right up to a truck carrying diamonds intended for a flight to Antwerp. With plenty of people watching, the team forced the drivers out of the truck at gunpoint, had them lie facedown on the ground, hopped into the truck and drove away.
Since the thieves obviously knew which truck to target and how to get their hands on KLM uniforms and a KLM truck (twice), police suspected inside help. Diamond merchants who lost millions in stones blame the airport's poor security. And the heist was actually the second time in six months that the cargo terminal had been infiltrated [source: BBC News]. Investigators haven't recovered the stones.
It's likely the diamonds stolen in the next entry on our list will never show up again, either. They're too famous.