Blue Diamond

The distinct blue color in these diamonds is caused by the presence of boron atoms trapped within the diamond's carbon crystal lattice. As boron concentrations increase, the intensity of the blue hue deepens. This natural process occurs deep within the Earth's mantle under extreme heat and pressure.

The Hope Diamond, a 45.52-carat deep-blue diamond, is arguably the most famous example in the world. It is currently housed in the National Museum of Natural History at the Smithsonian Institution in Washington, D.C. Another notable stone is the Oppenheimer Blue, which sold at Christie's auction house for over $50 million in 2016.

Blue diamonds are graded by gemological institutes like the GIA using specific color terms such as Faint Blue, Fancy Blue, and Fancy Vivid Blue. The grading evaluates the stone's hue, tone, and saturation. A 'Fancy Vivid Blue' grade represents the most valuable and intensely colored stones on the market.

Natural blue diamonds are exceptionally rare, making them significantly more expensive per carat than standard white diamonds. The price can reach into the millions depending on the color saturation, carat weight, and clarity. They are highly sought after by elite gemstone collectors and investors globally.