The biggest diamond stone in the world. Tiffany has unveiled most expensive Design in its history? It was last Sunday at a Tiffany event in Dubai, The World’s Fair Necklace the biggest diamond stone in the world was unveiled with a total 180 carats of diamonds, all set in platinum. At its center is an 80-carat oval shape, D color and internally flawless diamond that Tiffany has christened “The Empire Diamond,” named for the New York City icon in the jeweler’s hometown.

And it’s currently available for sale. While Tiffany declined to reveal the necklace’s sticker price, industry experts estimate that it would cost somewhere between $20 million and $30 million. It is the most expensive piece in the jeweler’s history after its famous 128.54 carat “Tiffany Diamond,” which is not for sale and has been labeled by Tiffany as “priceless.” While the Empire Diamond is for sale, Tiffany hopes that whoever purchases it will agree to lend the piece for special brand exhibitions.