Lab-Grown Diamonds

What Is a Lab-Grown Diamond?

A lab-grown diamond is carbon crystallized into diamond in a laboratory instead of the Earth's mantle. The chemical composition is identical: pure carbon arranged in a cubic crystal lattice. The hardness is identical: 10 on the Mohs scale. The refractive index, dispersion, thermal conductivity, and density are all identical. A gemologist cannot distinguish a lab-grown diamond from a mined diamond using standard instruments. Only specialized spectroscopic equipment can detect the subtle growth signatures that identify the stone's origin.

In 2018, the Federal Trade Commission revised its Jewelry Guides and removed the word "natural" from its definition of diamond. The FTC recognized that lab-grown diamonds are chemically, optically, and physically the same material as mined diamonds. A diamond is a diamond, regardless of whether it formed 90 miles underground over a billion years or in a laboratory over a few weeks.

That ruling changed everything. Lab-grown diamonds now account for over 55% of engagement ring sales in the United States. The average center stone has jumped from 1.3 carats in 2019 to over 2.5 carats today, because buyers who choose lab-grown can afford to go significantly larger for the same budget. The revolution didn't happen slowly. It happened all at once.

Project Superpressure: How It Started

The story begins in the 1940s, when General Electric launched a classified research program called Project Superpressure. The goal was straightforward: turn carbon into diamond. Scientists had been trying since at least 1797, when English chemist Smithson Tennant proved that diamonds are made of carbon. Every attempt for the next 150 years failed.

In 1954, physicists Howard Tracy Hall and Herbert Strong succeeded. Using a high-pressure belt press, they subjected graphite to temperatures of 1,600°C and pressures of 100,000 atmospheres. The carbon atoms rearranged into diamond. The stones were small, industrial-grade, and unsuitable for jewelry. But they were diamond. Confirmed, verified, tool-destroying diamond.

It took another 17 years before the first gem-quality lab-grown diamonds appeared (1971). And it wasn't until the 2010s that production technology advanced enough to make large, high-quality, colorless stones commercially viable for the jewelry market. The timeline from concept to revolution was 70 years.

CVD vs. HPHT: Two Ways to Grow a Diamond

CVD (Chemical Vapor Deposition)

The dominant method for gem-quality lab-grown diamonds today. A thin diamond seed is placed in a sealed vacuum chamber. Carbon-rich gas (typically methane) is introduced and superheated until it becomes plasma. Carbon atoms from the gas deposit onto the seed, layer by layer, atom by atom, growing a diamond crystal from the bottom up. The process takes several weeks for a 1-carat stone.

CVD diamonds tend to be Type IIa, the purest category of diamond. They generally achieve better color (D-F) and fewer inclusions than HPHT stones. Most high-quality colorless lab-grown diamonds on the market today are CVD-grown. The equipment is smaller and less expensive than HPHT presses, which is why production has scaled so rapidly in India and China.

HPHT (High Pressure High Temperature)

The original method, still widely used. A diamond seed is placed in a press with a carbon source (graphite) and a metallic catalyst (iron, nickel, or cobalt). The press subjects the assembly to temperatures exceeding 1,400°C and pressures of 5 gigapascals. Under these conditions, the carbon dissolves in the metal and recrystallizes as diamond around the seed.

HPHT is particularly effective for producing fancy colored diamonds (yellow, blue, pink). The metallic catalysts can introduce nitrogen (yellow) or boron (blue) during growth. HPHT stones may show metallic inclusions under magnification, a tell that gemologists use to identify the growth method. The equipment is massive: some HPHT presses weigh hundreds of tons.

Type IIa: Purer Than Almost Any Mined Diamond

Diamonds are classified into types based on the presence or absence of nitrogen and boron impurities. Type IIa diamonds contain virtually no nitrogen. They are the purest form of diamond, with exceptional optical transparency and the highest thermal conductivity. In nature, only about 2% of mined diamonds are Type IIa. The most famous natural Type IIa stones include the Cullinan Diamond, the Koh-i-Noor, and the Lesedi La Rona.

Most CVD lab-grown diamonds are Type IIa by default, because the growth process doesn't introduce nitrogen the way geological formation does. This means a lab-grown diamond is, by this measure, in the same purity class as the rarest 2% of natural diamonds. You can buy one for $150 to $250 per carat, sometimes less.

This is not a marketing claim. It's a classification established by the gemological community decades before lab-grown diamonds existed. The irony is structural: the most common lab-grown diamond is purer than the most exceptional mined diamond.

De Beers and the Lightbox Collapse

For decades, De Beers positioned itself as the defender of natural diamonds. The company controlled up to 90% of the global rough diamond supply through the 20th century and spent billions convincing the world that "A Diamond Is Forever." Lab-grown diamonds were publicly dismissed as threats to the industry.

Then, in September 2018, De Beers reversed course and launched Lightbox, its own lab-grown diamond jewelry line. The fixed price: $800 per carat. The message: lab-grown diamonds are "fun" but not "precious." It was an attempt to control the narrative by flooding the low end of the market and protecting natural diamond premiums.

It didn't work. Lab-grown prices continued to fall. Production in India and China scaled exponentially. By 2024, wholesale prices for 1-carat lab-grown diamonds had dropped to the $150 to $250 range, sometimes even lower. Lab-grown prices had fallen 74% since 2020 and show no sign of stabilizing. De Beers' fixed-price model collapsed under the weight of unlimited supply. In 2025, De Beers permanently shut down Lightbox. The world's largest diamond company entered the lab-grown market, failed, and retreated. Meanwhile, Anglo American, De Beers' majority owner, wrote down its diamond division by billions and put the company up for sale.

The Honest Trade-Off

We sell lab-grown diamonds because they are real diamonds at honest prices. But honesty requires acknowledging the full picture.

Lab-grown diamonds will not hold their resale value. Natural diamond prices have remained relatively stable. Lab-grown prices have dropped 74% in five years and will likely continue to decline as production scales. If you are buying a diamond as a financial store of value, buy natural. If you are buying a diamond to wear and enjoy, lab-grown delivers the same physical experience at a fraction of the cost.

Lab-grown diamonds are not automatically "eco-friendly." The growth process is energy-intensive. Some producers use renewable energy. Many use coal-fired grid power, particularly in India and China. The FTC has warned lab-grown sellers against making unsubstantiated environmental claims. We don't make them. We tell you what the stone is and what it costs. The rest is your decision.

What we can say with certainty: the diamond on your finger is diamond. Ten on Mohs. Type IIa purity. Indistinguishable from mined under standard examination. Certified by IGI. Sold with a Transparency Manifest showing every dollar. That is the TrueSanity position on lab-grown diamonds.

A Note on Terminology: What "Lab-Grown" Actually Means

The terms "lab-grown," "laboratory-created," and "synthetic" all legally refer to the same thing: a gemstone with essentially the same optical, physical, and chemical properties as its natural counterpart. The FTC's 2018 Jewelry Guides confirm this. However, the FTC removed "synthetic" from its recommended descriptors because consumers frequently confuse "synthetic" with "fake." We use "lab-grown" for clarity.

What we sell: Lab-grown diamonds. Real diamond. Pure carbon crystallized in a cubic lattice. Same chemistry, same hardness (10 Mohs), same optical properties as mined diamond. Grown via CVD or HPHT. Certified by IGI.

What we do not sell: Cubic zirconia (CZ), glass, nano crystal, or any other diamond simulant. These are entirely different materials with different chemistry, different hardness, and different optical properties. They are not diamond in any sense. Many sellers label these as "synthetic diamonds" or use ambiguous language to blur the line. We don't. If it's not carbon crystallized as diamond, it doesn't appear in our inventory. Ever.

Lab-Grown Diamond Buying Guide

What Matters

Cut quality. The single most important factor in how a diamond looks on the finger. A well-cut lab-grown diamond with good proportions and symmetry will outperform a poorly cut natural diamond of any grade. Prioritize cut above all else.

Color. Over 85% of lab-grown diamonds sold today are colorless (D-F). Near-colorless (G-H) stones offer excellent value with differences invisible to most people in a setting. Go no lower than I for white gold or platinum settings.

Carat size. Lab-grown diamonds let you go bigger for the same budget. The average lab-grown center stone in engagement rings has jumped to over 2.5 carats. Think about the visual impact you want, not the number you grew up thinking was standard.

What Doesn't Matter

Clarity (mostly). Over 95% of lab-grown diamonds fall in a narrow band of high clarity. VS1 and above is the norm. If the stone is eye-clean, a higher clarity grade adds cost without visible improvement.

Growth method anxiety. CVD and HPHT both produce real diamond. CVD dominates the colorless market. HPHT excels at fancy colors. Both are certified by IGI. Choose the stone, not the process.

Brand premium. A lab-grown diamond is a lab-grown diamond. The setting, craftsmanship, and margin are where brands differentiate. Our Manifest shows you exactly where your money goes.