It’s hard to believe, but people once seriously argued whether it was inevitable that lab-grown diamond prices would go down. At this point, the general direction is pretty clear, even if the magnitude of the decline has surprised even lab-grown skeptics, and—perhaps more surprisingly—has come in spite of fast-growing acceptance of lab-growns by U.S. consumers and retailers.

Yet for years, people in the synthetic diamond industry have assured the trade (and consumers and investors) that prices would stabilize. They were not correct.

I debated whether or not to print this blog, because I like a lot of the people who made these comments, and I believe they made them in good faith. And, of course, the natural diamond industry’s predictions aren’t perfect either.

But when you see something repeated over and over, even if it doesn’t appear to be true, pointing that out is a good lesson in humility for us all.

(Keep in mind that, in response to a complaint from Diamond Foundry, the National Advertising Division warned diamond companies against making these kind of predictions. That hasn’t stopped them.)

Let’s start nearly five years ago, right after the debut of Lightbox, when the lab-grown business first began taking off:

October 2018

“[Many believe] lab grown diamonds will lose value over time. This is a tragic, yet common misperception.”

—CVD Diamond

January 2019

“Market dynamics bode well for stabilization: Despite predictions by many in the mined diamond sector that prices for lab-grown diamonds will decrease as technology and capacity increases, this has not been the case to date.”

—International Grown Diamond Association report (excerpted here)

January 2019

“There is presently a massive shortage in the supply of lab-grown diamonds, which is causing a price increase. We believe this shortage will persist for several years.”

—Martin Roscheisen, CEO, Diamond Foundry, to Rapaport

February 2019

“Prices for aboveground diamonds are increasing lately despite De Beers’ attempt at promoting a PR agenda of dropping prices.…

In fact, we now believe the industry is in a situation much like at the beginning of many new industries—where systemic supply shortages stretch out for years. For example, when the wind power industry first started to take off, there was soon a supply shortage of turbines that kept many planned projects from being realizable, and this shortage lasted 5-7 years.…

At this point, if a Signet brand wanted to offer consumers the choice of manmade diamonds, it would not be able to find any supply through at least 2019.”

—Diamond Foundry’s blog

(Signet started selling lab-grown diamonds at all its stores in 2019.)

July 2020

“We are seeing stable prices in the larger, better-quality stones. We don’t see those prices going down.”

—Richard Garard, cofounder, International Grown Diamond Association, to JCK

October 2020

“Prices have definitely stabilized or have actually gone up in the last couple of weeks in the larger sizes.… I see prices stabilizing and likely going up over the course of the next six to 12 months.”

—Sue Rechner, then CEO of WD Lab Grown Diamonds, to JCK

December 2020

“We don’t anticipate substantial price movements up or down in the near future for lab diamonds.”

—With Clarity cofounder Anubh Shah to The Zoe Report

October 2021

“The market price of lab diamonds has fluctuated a lot over the years, but it has been stabilizing lately.”

—The Lab Mine

January 2022

“Prices have stabilized and will continue to as overseas markets and luxury brands test the waters.”

—Marty Hurwitz, CEO of MVI Marketing, to Southern Jewelry News

June 2022

“[As] the industry [becomes more] mature, the prices are [stabilizing] in every sector, from small to big sizes.”

—Smiling Rocks CEO Zulu Ghevriya, to Rapaport

February 2023

“Lab-grown diamond prices stabilizing.”

—The MVEye

June 2023

“I really feel like the [lab-grown] prices can’t fall a lot lower now, because we’ve reached a stage where growers are not able to produce at the cost that their stones are selling at in today’s market.”

—Miraj Patel, Greenlab, in Rapaport

August 2023

“The price of LGDs has rock-bottomed and has now stabilized.”

—Pooja Seth Madhavan, founder and CEO of Limelight Lab-Grown Diamonds, to India’s Economic Times

It’s certainly possible that with lab-grown diamonds now selling for a reported 99% off the Rapaport list, prices might bottom out. There’s not much further they can sink, other than free. (Some are testing that, though.) Still, when you talk to people who sell lab-growns—in private rather than public—they are mostly resigned to further drops.

With millions more carats being produced and possibly coming on the market, my sense is we’ll see a lot more “stabilizing” for lab-grown prices, but I’ll hold off on making predictions. That often doesn’t work out.