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They sparkle just as brilliantly, and even a jeweler’s loupe can’t detect any difference between diamonds grown in a laboratory and those forged deep within the earth over millions of years.

Now consumers and a growing number of jewelers have concluded that synthetic diamonds — chemically and physically identical to those produced in nature — have a bright future, offering the look and feel of their natural counterparts at a fraction of the cost. Evidence is mounting in their favor.

In just three years, the gems have captured 15 percent of the market for engagement rings in Houston, local appraiser Jessica Khurana said. The intense global pushback from traditional retailers might even be shifting as well. Last month, industry leader De Beers announced its own lab-grown diamond brand, Lightbox Jewelry, offering synthetic sparklers at much lower prices than mined ones.

The De Beers decision confirmed the hunch of Laura Chavez, a Rice alum whose London-based Lark & Berry jewelry brand deals exclusively in lab-made gemstones, including diamonds, to appeal to environmentally and socially conscious consumers as well as those looking for a good deal. Lark & Berry launched in May and will open its first retail store in London later this month.

“Once customers see the quality, they will buy,” Chavez said by phone.

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James Shigley, lead researcher at the Gemological Institute of America, assured that both natural and manmade diamonds indeed are diamonds. Though their origins differ, the gems are so similar that it takes specialized equipment and training to tell them apart.

The naked eye won’t suffice.

The first synthetic diamonds were produced in the 1950s for industrial use, Shigley said. General Electric researchers created the first line that could be faceted as gems in 1970. By the 1980s, however, synthetic diamonds were still mostly small and yellow in color.

Since then, the production process has improved and today yields colorless, gem-quality diamonds.

Local retailer Wolf Diamonds began selling laboratory-grown diamonds in 2014. Owner Bryan Vaughn was already aware of synthetic sapphires and rubies, which were available in the retail consumer market well before synthetic diamonds.

He saw a potential game-changer in the high-quality, manmade diamonds.

Vaughn’s Galleria-area store and Robbins Brothers were early adopters in Houston. Vaughn said his sales of laboratory-made diamonds have risen 50 percent annually and show no sign of slowing any time soon.

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But he does see competition. In the last 18 months, he said, the number of local retailers carrying laboratory-grown gemstones has increased to more than 20 from about two.

Vaughn said De Beers’ entry into the retail side of synthetic diamonds — after decades of producing them for industrial purposes — helped boost the legitimacy of manmade gems in the consumer market.

Retailers like Vaughn and Chavez say the main allure of laboratory-grown diamonds is their price, typically about half what natural diamonds can fetch.

They also appeal to customers turned off by the environmental hazards of mining, Chavez said, as well as tales of the blood diamond trade that fueled war in many African countries.

Chavez, who plans to expand Lark & Berry with a storefront in New York next, and possibly in Houston, also sees the synthetics as a means for younger women to afford to buy fine jewelry for themselves and then actually wear the diamonds more to special events instead of storing them in hope they will rise in value.

“It’s more of a sustainable investment,” she said.

But assessing the relative value of diamonds can be complicated. Khurana, whose appraisal work mostly involves natural diamonds, considers the laboratory-grown contemporaries to be a technology product that can be reproduced with precision in a controlled environment using advanced machinery.

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Over time, technology products such as phones or television sets tend to become less expensive. As of yet, it is unclear how current prices will shift as technology advances and it becomes easier to grow diamonds from carbon in a laboratory setting.

Those prices can vary wildly. A roughly 1-carat synthetic diamond at Wolf Diamonds can go for about $3,600, but at Lightbox, formed under the De Beers Group's Element Six business, that gemstone would be $800.

Lightbox bases pricing on the cost of making the synthetic diamonds rather than as a percentage discount from what a natural diamond would be, head of marketing Sally Morrison said.

“We think this is the right price and we think it’s sustainable,” Morrison said.

Then there’s the issue of grading systems.

The Gemological Institute of America created a simplified version of its natural grading chart for synthetic diamonds in 2006 and doesn’t plan to make changes, according to its lead researcher. But the Gem Certification & Assurance Lab, another group that grades synthetic diamonds, argues that rubrics can be more detailed for a better assessment of these gems.

Producers are also sensitive about how the synthetics are marketed. Retailers may inform customers about which of their products are synthetic or natural, yet organizations like the Diamond Producers’ Association call for further distinctions and more consumer education. They say the time it takes diamonds to develop in nature makes them rare, authentic and, therefore, more valuable.

“Natural diamonds and synthetic diamonds are distinct products with distinct markets,” a spokesman for the group said in an email. “Natural diamonds for luxury jewelry and synthetic diamonds for fashion jewelry.”

The value question ultimately will be settled by consumers of all ages.

And though researchers, appraisers, and retailers alike don’t expect lab-grown to overtake the market for natural diamonds anytime soon, they do expect the demand, particularly from millennials, for manmade diamonds to remain strong for years to come.

Ileana Najarro covers race, labor and immigration. She formerly covered small business and the intersection of immigration and the economy. She previously interned at the Los Angeles Times, the Mexico City bureau of The Wall Street Journal, The New York Times, and The Washington Post. She graduated from Stanford University with a B.A. in Communication, Departmental Honors and Phi Beta Kappa distinction.

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