Are you overpaying for a lab-grown diamond?

Marketed as an alternative to mined diamonds, lab-grown stones are growing in popularity among engaged couples, taking some of the shine from mined or “natural” diamonds, which have traditionally dominated the market.

When Toronto residents Daniel Ng and Olivia Chan were ring-shopping in 2024, choosing a lab-grown diamond was an easy decision, largely because of the significant price difference compared to a natural stone. 

Experts say a lab-grown diamond can cost 90 per cent less than its natural equivalent. 

“The tide has shifted. Like, more people are going with … the lab-grown,” Ng said.

Industry experts say lab-grown diamonds are becoming cheaper to make and more widely available, and confirm that more young couples are going with that option. But a Marketplace investigation found that virtually identical lab-grown diamonds are being sold at vastly different prices, raising questions about whether some consumers are paying far more than they need to.

CBC journalists bought two lab-grown diamonds, one from leading online jewelry retailer Blue Nile and the other from a vendor on the online marketplace Alibaba.com.

Both diamonds had the same features: one carat, D-colour, ideal cut, VS1 clarity and round shape. 

The Blue Nile diamond cost $1,639.23 Cdn, including shipping and taxes. The diamond purchased from Alibaba cost $228.86, all-in. 

Marketplace reviewed prices at other online retailers and found comparable stones listed for as much as $1,500 before fees and taxes.

Ng said the price he paid for Chan’s ring felt like a good deal. He proposed with a D-colour, 2.33-carat, VVS2 lab-grown diamond in May 2025, and said the entire ring cost less than $6,000 Cdn.

The couple was shocked at the cost of the Alibaba diamond.

“We had no idea,” Chan said. 

Why prices for similar lab-grown diamonds can vary

Paul Zimnisky, a U.S.-based diamond industry analyst and independent board member of Lipari Mining Ltd., said he has seen price gaps like this, warning they could create “credibility problems” for the industry.

“I think there’s definitely been an incentive for jewellers to sell the lab-grown diamond, because the profit margin potential is much higher,” he said. “The sales pitch has been, you know, ‘This is still a diamond, and instead of spending $6,000 [US, on a ring], you could get this for $1,000 or $2,000.’”

He said “it doesn’t change the fact” that the seller probably bought the lab-grown diamond “at wholesale for 75, 85, 95 dollars.” 

“With the man-made diamond, all of them are good-enough quality for jewelry, so they’ll just keep producing them,” he said. “It’s…