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The Hope Diamond: This 45.52 fancy deep blue diamond is gorgeous, to be  sure, but also deadly - at least according to some. The Hope’s story  starts with the Tavernier Blue, a crudely cut triangular stone of about  115 carats that was sold to King Louis XIV in 1669. Several years later,  Louis had the stone cut down to about 67 carats and had it suspended on  a gold ribbon so he could wear it on formal occasions. He renamed the  new cut the “French Blue.” In the mid 1700s, Louis XV had the gem set  into a pendant and it was much speculated that Marie Antoinette wore it;  the curse is the reason she was beheaded. Not so, say most historians:  there’s no evidence that it ever adorned the doomed Queen. The French  Blue mysteriously disappeared in a jewel heist in 1792 and never turned  up again. However, the Hope Diamond suddenly arrived on the scene just  as the statute of limitations on the jewel heist was running out 20  years later. It 
happened to be the exact same color as the  missing French Blue, although it had been cut differently and was  decidedly smaller. The Hope had several British owners throughout the  1800s, although, surprisingly, it never came into the hands of the Royal  Family. By 1910, famed jeweler Pierre Cartier had acquired the blue  beauty and sold it to 

American  socialite Evalyn Walsh McLean. She wasn’t interested until he reset the  old stone in a modern setting and told her tales of the curse. She wore  the stone for 37 years (and often let her dog wear it around the house  as well) and left it to her grandchildren upon her death in 1947.  However, she was quite in debt, and her trustees ended up selling it in  order to pay of some of the money she owed.     
That’s  how Harry Winston ended up owning it until 1958, when he decided that  it belonged to the Smithsonian and sent it there in an uninsured brown  paper envelope. It’s still part of the Smithsonian today, and so is the  envelope (that’s it above). And if you want to read a list of some of  the people supposedly killed off by the Hope’s curse, you can find a few  here.