Lab-grown diamonds come with sparkling price tags, but many have cloudy sustainability claims

Lab-created diamonds come with sparkling claims: that they are ethically made by machines running on renewable energy. But many don't live up to these claims or don't respond to questions about their electricity sources, and lab diamonds require a lot of electricity. They are chemically the same as diamonds found in the ground but cost a fraction of the price.

Fans of mined diamonds counter the marketing campaigns, saying natural diamonds hold their value better for longer and are more rare, thus more special.

In the U.S., lab-grown diamond sales jumped 16% in 2023 from 2022 and had a market share of 10% out of all diamond jewelry sales.

Social media posts show Gen Zs and Millennials proudly explaining the purchase of their lab-grown diamonds for sustainability and ethical reasons. But how sustainable they are is questionable, since making a diamond requires an enormous amount of energy and many big companies that do it are not transparent about their operations.

At Bario Neal, a jewelry store in Philadelphia, all of the lab-grown diamonds are either made with renewable energy, captured carbon, or are carbon neutral through credits purchased by the diamond manufacturers.

But that's not the norm for lab-grown diamonds.

Many of the companies are based in India, where about 75% of electricity comes from burning coal. They use words like “sustainable” and “environmentally-friendly” on their websites, but don't post their environmental impact reports and aren’t certified by third parties.

Lab diamonds are often made over several weeks, by subjecting carbon to high pressure and high temperature that mimic the natural conditions that form diamonds beneath the Earth’s surface. The technology has been around since the 1950s, but the diamonds produced were mostly used in industries like stone cutting, mining and dentistry tools.

Over time the laboratories, or foundries, have gotten better at growing stones with minimal flaws and production costs have dropped as technology improves. That means diamond growers can manufacture as many stones as they want and choose their size and quality, which is causing prices to fall rapidly. Natural diamonds take billions of years to form and are difficult to find, making their price more stable.

This article was provided by The Associated Press.