The Oppenheimer Blue sold on Wednesday for more than $57.5 million including fees at a Christie's auction in Geneva, making it the most expensive diamond ever sold.

Like boron, which gives diamonds a beautiful blue hue ... To get a closer look, we visited the jewelry company Suna Bros of NYC. More from So Expensive Narrator: Rihanna wore a $130,000 chocolate ...

Blue diamond is considered as the most expensive gemstone in the world ... In Stephen's presentation, during an event organized by luxury jewelry brand Tessera, he explained the 4Cs in diamond ...