The prices of natural diamonds have kept declining this year as more affordable lab-grown gems become increasingly popular among consumers, industry reports showed.

Natural diamond, or rough diamond, is a diamond that has not been or just simply been cut or processed. The price of rough diamonds has dropped by nearly 14 percent since the start of 2023, reporting a 24.8-percent draw-down from its peak, according to the latest data from Paul Zimnisky, a leading global diamond industry analyst.

As De Beers has dominated the global natural diamond industrial chain, its revenue performance is also a reflection of the downbeat demand of natural diamond market.

The company's sales of rough diamonds came in at 370 million U.S. dollars in August (the seventh sales cycle of the year), down 42 percent year on year and 10 percent from the previous month. This also marked a fourth consecutive month of sales decline.

De Beers CEO Al Cook attributed the sales drop to consumer's caution towards luxury products. "With the prevailing economic environment leading to softer end-client demand for diamond jewelry in key consumer markets, and the traditionally lower levels of midstream trading during the summer period, sightholders continued to take a prudent approach to their purchasing during the seventh sales cycle of the year," he said.

Meanwhile, global boom in synthetic diamonds is driving down prices of natural diamonds. Lab-grown diamonds are identical to mined ones, but sold at much lower prices.

The market share of synthetic diamonds has continued to expand since 2021 and reached a tipping point now. Of all the loose diamonds sold by U.S. specialty retailers in July, 49.9 percent were lab grown, showed data released by trend analytics company Tenoris.

The global market for synthetic diamonds was estimated at 14.5 billion U.S. dollars in the year 2022 and is projected to reach a size of 21.4 billion dollars by 2030 with a compound annual growth rate of five percent, according to the newly-updated Synthetic Diamonds - Global Strategic Business Report by Research and Markets.