Diamond And Ruby Trinkets Of The 'Queen's' Jewel Case

6. Heart of the Ocean Diamond

Sticking with the blue diamond theme, this next piece is a perfect example of life imitating art. In 1997 Leo DiCaprio and Kate Winslet went on a boat ride that didn’t turn out too well. The Titanic sank and Celine Dion sang a song that has become associated with the ship and film. One of the iconic props from the film was a necklace known as the Coeur de la Mer which Kate Winslet’s character.

In all seriousness, after the film, famed jeweler Harry Winston created a replica of the necklace using real jewels. At the ‘heart’ of the piece is a 15-carat blue diamond. Gloria Stewart, the actress who played the elderly ‘Rose’ in the film, wore the creation to the Oscars.

7. The Zoe Diamond

In 2014 the collection of Rachel Mellon, wife of the late philanthropist Paul Mellon, came up for auction at Sotheby’s. The pinnacle of the collection, and most sought after by potential buyers, was the Zoe diamond. This particular stone was classified as a 9.75 carat fancy vivid blue diamond. Originally believed capable of fetching around $15 million, the Zoe diamond shocked everyone when the winning bid came in at $32.6 million.

This makes the Zoe diamond not only the most expensive blue diamond in the world, but also the most expensive diamond in terms of price-per-carat ($3.3 million).