The following are excerpts from the Gemological Institute of America (GIA), a long-standing scientific authority and unique source for diamond knowledge. To read the full GIA articles please visit their website

A laboratory-grown diamond is the result of a technological process, as opposed to the geological process that creates natural diamonds. Laboratory-grown diamonds have essentially the same chemical composition, crystal structure, optical, and physical properties of diamonds found in nature. Most laboratory-grown diamonds are categorized as either high-pressure, high-temperature (HPHT) or chemical vapor deposition (CVD) diamonds, depending on the method of their production. Since HPHT and CVD diamonds are virtually identical to natural diamonds, differences only become clear when they are analyzed in a gem laboratory.

A laboratory-grown diamond (left) and a natural diamond (right) can appear identical to the naked eye.

Created diamonds are grown in a laboratory and have essentially the same chemical composition, crystal structure and physical properties as natural diamonds. They are not fakes, but they’re not natural.

When it comes to engagement rings, natural diamonds continue to occupy center stage. But there are newcomers on the block vying for attention. Once considered suitable only for industrial use, created diamonds are now available in gem quality. Today they are offered in sizes and colors that make them viable options for engagement rings and fine jewelry. As you explore your engagement ring options, it pays to learn a little about them.

Brilliant Earth allows consumers to pick their own diamonds – natural or created – and build their own rings. Pictured here is the Alvadora, a vintage-inspired ring featuring a bezel-set center gem surrounded by lavishly detailed latticework and a halo of shimmering melee. Courtesy: Brilliant Earth

Jewelry designer Scout Mandolin pairs an emerald-cut created diamond with slender tapered created diamond baguettes for a streamlined and elegant version of a traditional classic. Courtesy: Scout Mandolin, scoutmandolin.com

Scout Mandolin accents the center stone in his Allure Emerald Cut ring with straight baguettes and pavé set round brilliant cut diamonds. Courtesy: Scout Mandolin, scoutmandolin.com

How Are Created Diamonds Made?

While natural diamonds may take billions of years to form, created diamonds can be grown in a matter of weeks, using one of two processes:

1. High Pressure, High Temperature (HPHT): With this method, a created diamond is produced in a laboratory by mimicking the high-pressure, high-temperature conditions of natural diamond formation in the earth. The result is a distinctive crystal shape that is, for the most part, a combination of octahedral and cube faces with a flat base.

2. Chemical Vapor Deposition (CVD): With this newer technique, created diamonds are grown in an apparatus that uses moderate temperatures and very low pressures in a vacuum chamber. The CVD process involves heating a mixture of a hydrocarbon gas (such as methane) and hydrogen, which releases carbon atoms that then settle onto the cooler, typically square-shaped seed plate of natural or, more likely, synthetic diamond. This results in a square-shaped, tabular synthetic diamond crystal.

Do CREATED Diamonds Look like Natural Diamonds?

Created diamonds have nearly the same physical and optical properties of natural diamonds. They are just as hard, and they are available in a range of colors and qualities. Just like natural diamonds, they can have an excellent cut—and, therefore, excellent fire, brightness and scintillation—or they can have a poor cut or anything in between. It all depends on the quality of the created diamond and the skill of the cutter.

What about Colour?

Most HPHT created diamonds are yellow or brown as grown, although some blue and near-colorless crystals are also produced. HPHT processes can also be used to enhance the yellow color or dramatically remove unwanted color so the diamond is on the colorless to near-colorless D-to-Z scale.

Most HPHT created diamonds are yellow as grown and can be enhanced by post-growth treatments to change, improve or remove the color. Copyright: GIA & Tino Hammid

Irradiation, sometimes followed by high-temperature heating, is another common treatment process. It can change a created diamond’s color to yellow, red, pink or green. Natural yellow, red, pink and green diamonds can be prohibitively expensive. created diamonds offer a more affordable alternative.

Created diamonds can be found in a variety of attractive colors. The yellows set in jewelry range from 1.00 to 1.25 ct; the loose lab-grown diamonds are all less than 1 ct. The colorless diamond accent stones are natural. Photo: (Diamonds) Harold & Erica Van Pelt/GIA. Courtesy: (Jewelry) Gemesis Corp.

The Bottom Line

Created diamonds have nearly the same physical and optical properties of natural diamonds. They are just as hard, and they are available in a range of colors and qualities. Just like natural diamonds, they can have an excellent cut—and, therefore, excellent fire, brightness and scintillation—or they can have a poor cut or anything in between. It all depends on the quality of the created diamond and the skill of the cutter.

These CVD created diamonds display the same color and brightness of comparable quality natural diamonds. They range in size from 0.24 to 0.90 ct. Photo: Robert Weldon/GIA