What’s The Difference Between Natural And Lab-Grown Diamonds?

If you’ve bought a piece of fine jewelry containing a diamond in recent years, you’ve likely encountered a more affordable option in a lab-grown diamond — especially if you were in the market for an engagement ring.

While you may shell out around $23,000 for a 2-carat halo ring of natural diamonds, the lab-grown version of the same ring might cost $6,000 — a staggering difference for two options that are visually, chemically and physically the same.

Laboratory-grown, or synthetic, diamonds are more popular than ever as consumers are drawn to their affordability compared to mined, or natural, diamonds. Plus, sustainability and ethics are now top of mind for many diamond shoppers, even more so since the 2006 film “Blood Diamond” shed light on many of the inhumane practices in traditional diamond mining.

But when you ask the experts, the differences between mined and lab-grown diamonds aren’t so cut and dry — especially where ethics and sustainability are concerned. We talked to four industry experts to break it down.

As the name implies, lab-grown diamonds are created in a laboratory, rather than harvested from nature. “Technically speaking, there are two ways of producing lab-grown diamonds,” explained Avi Levy, the president of North America for the International Gemological Institute. “The first is the high-pressure, high-temperature (HPHT) method, where heavy mechanical presses and intense heat are combined to replicate the conditions under which natural diamonds formed. The second is chemical vapor deposition (CVD), a process that superheats gas into plasma, releasing carbon atoms to ‘build’ a diamond crystal at the atomic level.”

Both methods actually start with a tiny piece of a mined diamond. “A sliver of a natural diamond ‘seed’ [is] placed in a chamber,” said Anna Bario, co-founder of Bario Neal, which sells both lab-grown and natural diamonds. “The lab then adds carbon and heat, mimicking the way that diamonds form naturally in the Earth. The seed then grows and grows into a high-quality diamond.”

And while “both of these methods grow real diamonds,” said Levy, “one process (CVD) assembles the diamond in vertical layers and the other (HPHT) uses a metal catalyst to dissolve component carbon. These different approaches may produce microscopic inclusions (internal characteristics) which differ from those seen in natural diamonds, but not always. Once polished, both HPHT and CVD produce gemstones that look identical to natural diamonds.”

According to the experts, there is no way for the average person to differentiate a natural from a lab-grown diamond. “There are no differences to the naked eye,” Levy said. “Lab-grown diamonds are real diamonds, scientifically, chemically, physically and optically. You can only separate natural and lab-grown diamonds with sophisticated testing.”

They’re also identical when it comes to hardness, both scoring a 10 (the highest value) on the Mohs scale, which is used to define hardness of materials. 

There are two ways that trained experts can spot a synthetic diamond. “There are small but significant differences in inclusions and growth structure that allow a trained gemologist to distinguish between natural and lab-created diamonds. These differences may only be identified under extreme magnification,” said George Leifheit, vice president of global strategic sourcing for Signet, the parent company of Kay, which sells both lab-grown and natural diamonds.

Another method is by a tiny inscription, which is required in a lab-grown diamond. “Per the U.S. Federal Trade Commission, all lab-created diamonds are required to carry the label ‘lab-created’ or ‘lab-grown’ so the consumer can have confidence in the diamond they are buying,” added Leifheit.

Since visually and chemically, the two vareities are the same, the biggest discernible difference is the price point — and it’s a substantial one. When picking a lab-grown diamond over a natural one, “you can frequently double the carat weight for the same budget,” Levy said.

Diamonds are graded based on their clarity, cut, carat and color (known as the four Cs). If a natural diamond and a lab-grown diamond rank equally in all four categories, the lab-created version will be significantly cheaper — about 20-30% cheaper on average, estimated Leifheit, adding, “The price difference will increase as the carat size goes up.”