Natural diamond prices fall to record lows as lab-grown stones gain share

Natural diamond prices reached their lowest level this spring, according to the Diamond Standard Index. The index fell 68% from its 2011 peak. Lab-grown diamonds now account for 61% of engagement ring purchases, up 239% from 2020 levels, a survey by the wedding planning platform The Knot found. Unit sales of lab-grown stones between 1.05 and 1.09 carats grew 3% year-over-year in 2025.

Market split emerges The Diamond Standard Index tracks investment-grade diamonds.

Sales of natural diamonds weighing 2.5 to 2.74 carats rose 19% last year, while stones 1.99 carats and below generally declined. Half-carat brown diamonds posted roughly 200% year-over-year unit sales growth in May. Elongated shapes such as oval and marquise saw prices rise about 25% over several years.

Broader pressures Global demand for natural diamond jewelry remained flat in 2025 after three years of declines, data from the diamond miner De Beers showed. China’s personal luxury goods market contracted as much as 5% last year. The share of U.S. households made up of married couples stood at 47% last year.

Lab-grown diamonds have also changed consumer perceptions of diamond value, analysts told Business Insider.