Grown, Not Mined: Lab Diamonds and the New Price of Brilliance

The terminology war tells the story. GIA began grading man-made diamonds in 2006 with a Synthetic Diamond Grading Report that used descriptive terms, colorless or near colorless, VVS, VS, SI or I, rather than specific 4Cs grades. In April 2019, following the US Federal Trade Commission's revised Jewelry Guides, the document became the Laboratory-Grown Diamond Report. In August 2020 GIA moved to the same specific color and clarity grades used for natural diamonds, citing growing acceptance. On 1 October 2025 it reversed course: the printed Laboratory-Grown Diamond Quality Assessment classified stones as Premium or Standard, priced at $15 per carat, and CEO Pritesh Patel said GIA would no longer use the nomenclature created for natural diamonds to describe what is a manufactured product. In August 2026 GIA launched LGDR by GIA, digital-only reports carrying specific color and clarity scores, while reserving the word grading for natural diamonds, echoing the 2026 CIBJO recommendation that synthetic reports be titled Laboratory-Grown Diamond Product Specifications. Four names in twenty years, and the direction of travel is clear: the industry now treats the two categories as separate products.

GIA will no longer use the nomenclature created for natural diamonds to describe what is a manufactured product. Pritesh Patel, GIA president and CEO, 2025

Two ways to grow a diamond

HPHT growth mimics the high-pressure, high-temperature conditions of natural diamond formation. CVD breaks down carbon-rich gas into carbon and hydrogen atoms deposited onto a diamond seed. The identification markers differ by method. HPHT material may show uneven color distribution, graining patterns and metallic flux inclusions with no strain patterns. CVD material may show even color distribution, no graining, banded strain patterns and occasional dark pinpoint inclusions. Both can show unusual fluorescence colors and occasional phosphorescence. The eye alone is never enough: screening devices such as GIA's iD100 use spectroscopy to separate natural from laboratory-grown diamonds down to 0.005 carats.

Color treatment is common in CVD material because many crystals emerge from synthesis machines with a brown tinge. Since early March 2026, GIA's lab-grown reports state specifically whether there is evidence of post-growth color treatment, no evidence, or that it is currently undeterminable, replacing the generic may have been treated line. The growth type, CVD or HPHT, continues to be stated. The trade debates whether as-grown, untreated stones deserve a premium, a question the new report language makes possible to ask precisely.

The 2026 price divergence

In September 2026 the fair market price for a 1-carat laboratory-grown diamond sat near $680, trading roughly $590 to $770, down 30.1 percent since March 2025. A natural 1-carat D/VVS2 sat roughly $4,500 to $7,000. Rapaport's RAPI index for 1-carat natural polished was flat in July 2026 at 3,880, ending thirteen straight months of declines, and was down 14.3 percent year on year. The two categories now serve different buyers.

The economics of production are under strain. An Indian grower told Rapaport that 1-carat-plus laboratory-grown prices fell 25 to 30 percent in the year to mid-2026, and that growers are not able to produce at the cost their stones are selling at. Retail economics remain thin: one US retailer buys 1-carat lab-grown wholesale near $400 and sells near $1,000, marking up 20 to 30 percent versus 40 to 45 percent for natural, with dollar profits squeezed since early 2023.

The cultural fact

Adoption has crossed the majority line in the American bridal market. Laboratory-grown stones were in 51 percent of new engagement rings in the first half of 2026 on BriteCo figures via local press, up from 6 percent in 2019, and The Knot's 2025 Real Weddings Study put laboratory-grown in 52 percent of 2024 couples' rings. The median laboratory-grown price fell from $4,622 per carat in 2019 to $2,057 in 2025, while natural rose from $6,237 to $8,428 per carat. Those figures reach us via secondary reporting rather than the primary BriteCo or Knot studies, but the direction is unambiguous.

A majority of new American engagement rings now carry lab-grown centers. That changes what diamond means to the next generation of buyers, and it is why the report vocabulary matters as much as the price. The stone is real. The category is now, officially, something else.

Editorial descriptions of gemstones, treatments, origins and auction results are researched to professional standards but do not replace laboratory testing, independent appraisal or authentication. See our Terms of Use.