The Regent diamond, famed for the purity of its cut, colour and clarity // The Regent diamond, famed for the purity of its cut, colour and clarity (R.M.N.)

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R.M.N.

The Regent diamond, famed for the purity of its cut, colour and clarity

In the diamond world, big = beautiful, right? But then cut, colour and clarity are all pivotal as well. And it's with that in mind that more than one diamond expert has called a 140.50-carat stone named The Regent the most beautiful diamond mankind has ever seen - despite its being only one-quarter of the bulk of the world's largest cut diamond. This flawless Indian gem adorned the crowns of the French kings Louis XV and Louis XVI, and later Marie Antoinette's hat and Napoleon's sword. Today it's in the Louvre.

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