Blue Diamonds

What Forms Blue Diamonds

Diamonds are a crystalline form of carbon, which when flawless and without any inclusions, is colorless. Most diamonds, however, do contain trace amounts of different minerals that subtly alter the crystal structure of the gem, forcing it to absorb and reflect color in slightly different ways, resulting in a visible coloration. The most common color tinge is brown or yellow, making diamonds of these colors less valuable. More uncommon colors, however, are often highly coveted, particularly if the color is distinct and rich. Diamonds are actually found in more than 300 different shades of color.

Natural blue diamonds are formed from minute traces of boron in the stone’s chemical composition, an inclusion that occurs in less than 0.1 percent of natural diamonds. The blue shade can range from a pale hint of color to a rich, steely shade similar to the Hope Diamond, one of the most famous blue gems in the world. A large amount of hydrogen in the stone can also create a blue hue.

Stones with a rich solid color are the most expensive – a blue-green or blue-purple shade will be less expensive, since it indicates the presence of more than one mineral impurity in the gem. The deeper the color, the more desirable the stone. While colored diamonds are fairly common, those with the deepest colors are termed “fancy” and are suitably more expensive.

Synthetic Stones

Synthetic diamonds can now be created to appease the demand for these luxurious colored stones, though artificial gems are significantly less valuable with little or no investment or resale appeal. Many times diamonds with undesirable colors (light tints, especially yellow or brown) will be treated to create rich, vibrant hues, but synthetic stones can also be grown with the same impurities that form natural blue stones. The most common process for lab-created stones is chemical vapor deposition, which involves injecting carbon dioxide into heated plasma to simulate the high temperature conditions under which natural diamonds form.

Treated Diamonds

It is much easier to treat inferior diamonds to improve their quality and appearance in order to create simulated blue diamonds rather than creating synthetic stones. Irradiation can alter the stone’s crystal structure to reflect blue light, resulting in a blue stone, while high pressure, high temperature (HPHT) treatments can “repair” flawed stones and in the process, create different, more desirable hues. A third type of treatment is coating, where a thin layer of color is applied to the stone in order to change its color.

All treatments are delicate and unpredictable: treated diamonds can change their color over time. Patrons who consider a treated stone should always examine the jewelry lab certificate to ascertain the extent of the treatment as well as any available warranties to cover potential changes in the future.

Blue Diamonds in Engagement Rings

Blue Diamond Pendant

Many couples are turning to colored gems for more distinctive, individualized engagement rings. Blue gems are rare and beautiful alternatives to traditional colorless diamonds, but their rich hue does impose some limitations on the ring’s design. To prevent a poor color comparison, blue stones are best set in white gold, platinum, or titanium. The setting should be suitably secure to prevent loss or damage to the valuable stone, particularly because its rarity will make it difficult to replace. Because of the expense of such an unusual stone, couples might want to consider alternatives such as treated diamonds or even substituting sapphires as a more affordable stone choice.

Blue diamonds are rare and unusual stones with rich, distinctive hues that every jewelry connoisseur can appreciate. Customers should always take appropriate precautions when purchasing rare gems, however, to insure they are not inadvertently buying a synthetic stone rather than a genuine precious gem. While more affordable options are available, few gems approach the exquisite beauty of a true blue diamond.