They say diamonds are forever, but it's become crystal clear the diamond industry is changing.

Pandora, the world's largest jeweler, sent shockwaves through the diamond industry when it announced earlier this month it would no longer sell mined diamonds, opting instead for lab-grown ones. The Copenhagen-based company citing sustainability and environmental concerns, becoming the latest major industry player to make the switch.

Lab diamonds are entirely man made and have the same physical and chemical properties as mined ones.

At Paris-based Diam Concept, a company that creates diamonds using the chemical vapor deposition method, founder Alix Gervel explained the process begins when a thin sheet of crystal, known as a diamond seed, is inserted into a reactor, where it's exposed to heat and a gas mixture.

As carbon atoms are deposited onto the seed, so grows the diamond. It takes about a month for the rock to fully form; it is by then quite literally a diamond in the rough, surrounded by what's known as polycrystalline. Final steps involve trimming, polishing, and evaluating the stones, which are graded according to the 4Cs-- cut, color, clarity and carat, just like mined diamonds.

"It's exactly the same," said Gervel, who explained one would need very sophisticated tools to be able to tell the difference between a lab diamond and a mined diamond.

"Lab-grown diamonds are the future," she added.

According to the Antwerp World Diamond Center, demand for man-made stones is expected to grow by up to 20% annually.

Price is a big part of the appeal; according to some estimates, lab-grown diamonds with nearly identical grades to a natural one can be up to 30% cheaper.

"With our system, the cost to produce them is actually higher, but because we don't have any intermediaries, we can sell them at a lower price," explained Gervel.

The sparkling stones have even made their way to Paris' iconic Place Vendome, home to some of the world's oldest and finest jewelers. Courbet is the first of its kind in Paris's center of jewelry and luxury -- a store that exclusively sells lab diamonds.

"We wanted to show the way in ecological luxury," said Marie-Ann Wachtmeister, who co-founded Courbet in 2018.

Those in favor of lab-grown diamonds argue the stones are more environmentally friendly. According to a 2014 report from Frost & Suillivan, mined diamonds require twice as much energy per carat than those grown in a lab, and that about 125 pounds of carbon are released into the air for every mined carat.

Gervel estimates about 44 pounds of carbon are produced for every carat she creates.

Wachmeister says many of her clients are environmentally conscious.

"They care about the environment. They want a piece of jewelry they can look at and feel good about," she said.

The mining industry counters that lab-diamonds still take energy to produce.

"When a lab-created diamond is grown in the so-called CVD (chemical vapor deposition) process using 100% renewable energy, greenhouse gas emissions are less than 1/10 of emissions from a low-carbon diamond mine -- this includes all upstream emissions in the lab-created diamond value chain," Pandora spokesperson Johan Melchior wrote in a statement.

But beyond the environmental debate, consumers are also growing increasingly mindful of where their stones of coming from, hoping to steer clear of so-called "conflict diamonds."

Progress has been made when it comes to working conditions in the mines, and thanks to initiatives like the Kimberly Process, meant to increase transparency and oversight in the diamond industry, the trade of conflict or "blood" diamonds has been reduced. But advocates say that human rights abuses are still rampant at many diamond mines.

Those in favor of mining, such as the Natural Diamond Council, argue the industry "employs tens of millions of people around the world and their families and communities depend on the income and welfare that the natural diamond industry provides."

"Shifting entirely to lab-grown diamonds essentially robs them of that opportunity for accessing the legal market," said Joanne Lebert, executive director of Impact, a nonprofit organization focused on trying to improve resource management in areas where human rights and security are at risk.

"If you if we shut the door on them, you're essentially condemning them to this vulnerability, human rights violations, poverty, et cetera, rather than being a solution in the sector," she said.

"This new emerging part of the industry is also creating a lot of new work opportunities. I'm not sure that in the long term these communities that are having work in the diamond mines are going to be sustained, because after 20 years the mine closes, and a lot of them are closing now," said Wachtmeister.

Just a few doors down from Courbet, jeweler Lorenz Baumer argues there's something irreplaceable about a natural diamond.

"You just happen to work with nature, which is really wonderful because it is full of surprises," Baumer said. "We're used to dealing with all sorts of interesting, different requests and making sure we find some special unusual stones. Sometimes the stone might even have a history."

Baumer currently only sells natural diamonds, yet he's not ruling out a future with lab-grown ones.

"If they're in line with my values, which are about excellence, beauty and authenticity, yes, why not?"

 abcnews.go.com