Blue diamonds are by nature among the rarest of natural color diamonds, and supplies are becoming scarcer and scarcer as the only mine in the world that produced really pure blue diamonds, in South Africa, has dried up and closed.
The blue diamonds that were produced in South Africa have a beautiful sky blue color that is very subtle and soft, but still clearly pronounced even in light blue stones.
In the Argyle mine in Australia, which is most famous for its production of pink diamonds, there is still a small production of blue diamonds, which will however come to an end in 2018 when the production in the mine is planned to close. The Argyle blue diamonds are different to the ones that were formerly produced in South Africa, in that they are often dark blue, and have a metallic glow to them, and often little streaks of gray, giving them a steel blue color. Some of them have traits of violet in them, which gives an exceptional color combination.
Blue is a color that changes with light, more than other colors, which is a spectacular an interesting feature. What is important to remember when looking for a blue diamond is that they are never blue like sapphires, but always either a sky blue or a darker metallic blue, with the unique exception of the Hope Diamond. It is also important not to have too strict criteria in terms of shape or size when searching for that perfect blue diamond, since they are becoming so extremely rare.
Read more about the origin of the color in natural blue diamonds here.