Blue diamonds sound unusual to some, but they are not as uncommon as you might think. Considered to be truly classy and elegant, a blue diamond ring is durable, beautiful and ideal for daily wear, something that some diamonds are not. A blue diamond ring is, for example, a great choice for a truly impressive engagement ring. And have you ever heard of the Hope Diamond? Yes, that stunning and iconic museum piece is a blue diamond too.

What Makes a Diamond Blue?

Most of us know, because we took basic science classes at school, that a diamond is the result of heated and pressurized carbon atoms coming together. The blue hue seen in the stones in a blue diamond ring is thanks to the presence of a much rarer element, boron, as well.

Boron makes up about 0.001% of the earth’s crust, so the chances that it will be present at a diamond's formation are pretty slim. That's why blue diamonds are so rare and so very coveted. Of all the colored diamonds they are the rarest and that is because it is so very unusual that boron gets mixed in with the carbon. But when it does, the results are the spectacular shades of blue one sees in the most attractive blue diamond rings.

A forming diamond will obtain a bluish color if the nitrogen content is low and there is boron present during its formation. If there is a higher concentration of boron, the intensity of the blue color will be higher as well, making the stone even more valuable.

Not all blue diamonds - or diamonds classified as blue - actually look very blue. Some have a greenish or gray tone, often because of impure nitrogen or even radiation having been present during their formation. In fact, you will find that most blue diamonds on the market have secondary hues in addition to the primary bluish hue, as a pure blue diamond is very, very hard to find.

Why are Blue Diamond Rings Such a Great Choice?

When used as an engagement ring, the appeal of blue diamond rings is rather obvious.

Who wouldn’t feel like a princess with a blue diamond ring, knowing how valuable and gorgeous the stone is. In addition, the symbolism of faithfulness, loyalty and sincerity that is associated with blue in the science of color psychology is an ideal sentiment for a couple about to take their relationship in a new direction.

But there are other reasons why a blue diamond ring is such a coveted, but sensible, choice. They are exceptionally hard, making them durable and practically scratch proof. And the fact that, to many, the 'fire' at the heart of a blue diamond is quite simply unmatched makes them ideal for use as a center stone for any type of ring.

Choosing a Blue Diamond

As is the case for any fancy colored diamond if you are in the market for a blue diamond ring it really is all about the color first and foremost. It can be hard to evaluate the color of a blue diamond, as often there are secondary colors present. In order to identify the exact color grade of the blue diamond, the three main aspects to take note of are hue, tone and saturation.

Hue

This refers to the primary or visible color tint of the stone. As previously mentioned, when dealing with blue diamonds gray or green are often secondary hues visible in the stone. If these tones overpower the blue, the overall value can be affected but that is not to say that the stone won't be truly stunning in its own right.

Tone

Tone refers to how light or dark the diamond is. If it's too light, the blue hue will appear faint and barely noticeable. If, on the other hand, the stone is too dark, it may come across as being more black than blue. Choosing the tone comes down to personal preference, but the best blue diamonds have a tone that is neither too dark nor too light.

Saturation

This refers to how strong the color of the blue in the diamond is. It goes without saying that the deeper and more vivid the blue color is, the higher the price of the stone (again, Google the Hope Diamond to see what we mean. That is a truly blue diamond.)

Once these aspects have been evaluated and graded, a specific color grade on the color scale for fancy-colored diamonds can be assigned to the stone.

The color grade scale is as follows: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Dark, and Fancy Deep. You'll see these terms as you shop for sure, and now you can make a better decision before you buy, because you know what they mean.