Turns out that’s not so, at least when it comes to value. The culprit: less costly, but equally sparkly, synthetic gemstones that are flooding the market.

For example, a 2-carat fabricated diamond runs for around $1,000 today, says Joel Levinson, vice president of Dynasty Jewelry and Loan in Norcross, Georgia. “You can’t tell by the naked eye that one is natural and one is lab, so people are choosing to spend a lot less money for what looks to be the same thing,” he says. And so, while natural diamonds remain more expensive, their value has diminished with less demand. Market prices for diamonds have dropped by 45 percent since a peak in March 2022, according to the IDEX Diamond Index.

Cost isn’t the only factor fueling the turn toward synthetics. Some younger buyers want jewelry produced without the taint of environmental damage or exploitative labor. About half of millennial couples now choose a lab-grown engagement ring, and two-thirds of Gen Z buyers select a synthetic stone, according to a survey by insurance agency BriteCo.

So how can you secure the best price for a diamond?

Clean it. Use a toothbrush and dish soap to remove dulling oil and dirt buildup. This can make the diamond appear well cared for, helping to fetch the best price, Levinson says.

Get it appraised. For about $150, an appraiser will detail the diamond’s weight and condition and record any minute cracks or chips. This gives the buyer more confidence in the stone’s quality. But don’t expect to get the full appraised value when selling, says Aleah Arundale, a wholesaler with Olympian Diamonds in Chicago, because resellers must leave room to mark it up for their operating costs and profit.

Get quotes from at least four local buyers. Those can include jewelers and pawnshops, Arundale says. Also, consider online auction sites such as Circa and Worthy, which reach a larger pool of prospective customers beyond your area. —June D. Bell