The Question Every Diamond Buyer Asks
At some point in the engagement ring research process, almost every buyer ends up asking the same question: are lab grown diamonds actually real diamonds? And if they are, what's the difference why does it matter which one you choose?
It's a fair question, and it deserves a straight answer rather than a sales pitch. The honest answer is that lab grown and natural diamonds are the same in most of the ways that matter and different in a few ways that are worth understanding clearly before you decide.
This guide covers every meaningful difference (and similarity) between lab grown and natural diamonds: the science, the appearance, the durability, the price, the ethics, and the resale value. No spin in either direction. By the end, you'll have everything you need to make a decision you're confident in.
First: What Actually Is a Diamond?
A diamond is a solid form of carbon in which every atom is arranged in a specific crystal structure called a diamond cubic lattice. This crystal structure is what gives diamonds their extraordinary hardness a 10 on the Mohs scale, the hardest naturally occurring substance on earth as well as their optical properties: the brilliance, fire, and scintillation that make them the most sought-after gemstone in the world.
That's it. A diamond is defined by its chemistry and crystal structure not by where or how it formed. A diamond grown in a laboratory has the same carbon atom arrangement, the same crystal structure, the same chemical formula (pure carbon), and the same physical properties as a diamond formed deep within the earth over billions of years.
This isn't a marketing claim. It's basic chemistry, confirmed by every major gemological laboratory in the world, including IGI and GIA. When IGI grades a lab grown diamond, they grade it using exactly the same criteria as a natural diamond the same 4Cs, the same instruments, the same standards because the material is the same.
How Lab Grown Diamonds Are Made
Lab grown diamonds are produced using one of two methods, both of which replicate the conditions under which natural diamonds form.
CVD (Chemical Vapour Deposition)
A thin slice of diamond (the seed crystal) is placed inside a sealed chamber. The chamber is filled with carbon-rich gas usually methane and heated to around 800–900°C. The gas is then ionised into plasma using microwaves or a laser, which breaks down the molecular bonds and allows individual carbon atoms to deposit onto the seed crystal, layer by layer, building a diamond from the bottom up over a period of weeks.
CVD is currently the dominant method for producing gem-quality lab grown diamonds. It allows precise control over the growth conditions, producing stones with consistent quality and relatively few inclusions. Most lab grown diamonds you'll encounter from reputable retailers including Unii Jewels are CVD grown.
HPHT (High Pressure High Temperature)
A diamond seed is placed in a press that replicates the extreme conditions found approximately 150km below the earth's surface roughly 1,500°C of heat and 1.5 million PSI of pressure. Carbon dissolved in a molten metal catalyst crystallises onto the seed and grows into a diamond over days to weeks.
HPHT was the original method for growing lab grown diamonds, developed in the 1950s, and is still widely used. HPHT diamonds sometimes contain trace metallic inclusions from the flux material, which can be identified using specialised spectroscopic equipment. These inclusions are noted on the certificate and are completely harmless.
How Natural Diamonds Form
Natural diamonds form approximately 150–200km below the earth's surface, where temperatures of 900–1,300°C and pressures of around 725,000 PSI cause carbon atoms to crystallise into diamond over periods of 1–3 billion years. They're then transported closer to the surface by volcanic activity through formations called kimberlite pipes, where they're eventually mined.
The process is the same in principle carbon crystallising under heat and pressure just at a vastly different scale of time and depth. A natural diamond is essentially doing slowly and naturally what a lab does quickly and deliberately.
Appearance: Can You Tell Them Apart?
No. Not with the naked eye. Not with a standard jeweller's loupe. Not with the instruments used in most jewellery stores.
A lab grown diamond and a natural diamond of the same cut, colour, clarity, and carat weight are visually indistinguishable. They have the same refractive index (how they bend light), the same dispersion (how they split light into spectral colours), and the same brilliance. The sparkle you see in a lab grown diamond is physically identical to the sparkle in a natural diamond of the same quality.
The only way to reliably distinguish a lab grown diamond from a natural diamond is with specialised spectroscopic equipment specifically, equipment that can detect the characteristic growth patterns of CVD or HPHT diamonds, or the presence of certain trace elements. This equipment is found in major gemological laboratories like IGI and GIA, but not in jewellery stores, and certainly not in the hands of friends, family, or anyone who might look at your ring at a dinner party.
This is why independent certification matters so much. The certificate not the stone's appearance is the definitive record of whether a diamond is lab grown or natural. It's also why IGI laser-inscribes the growth origin on the girdle of lab grown diamonds: to ensure the identity is permanently recorded on the stone itself, not just on paper.
Physical Properties: Are They Actually the Same?
Yes, in all the properties that matter for a piece of jewellery worn every day.
Hardness
Both lab grown and natural diamonds score 10 on the Mohs hardness scale the maximum. This is the hardness of the crystal structure itself, which is identical in both. A lab grown diamond is exactly as scratch-resistant as a natural diamond. Neither can be scratched by anything except another diamond.
Durability
Diamonds both lab grown and natural can chip or cleave if struck with sufficient force at the right angle. This is a property of the crystal structure (cleavage planes) rather than the origin of the stone. A lab grown diamond is no more or less prone to chipping than a natural diamond of equivalent quality. The setting style matters far more than the diamond's origin a well-set stone in a bezel or a four-prong setting is well protected regardless of whether it's lab grown or natural.
Thermal Conductivity
Diamond has extraordinarily high thermal conductivity it conducts heat faster than any other known material. Both lab grown and natural diamonds have the same thermal conductivity, which is why diamond testers (instruments commonly used in jewellery stores to distinguish diamonds from simulants like moissanite or cubic zirconia) cannot distinguish a lab grown diamond from a natural one. They both test as diamond.
Refractive Index
The refractive index of diamond the measure of how strongly it bends light is 2.417 for both lab grown and natural diamonds. This is what produces the characteristic brilliance and fire of a diamond. Simulants like cubic zirconia (2.15) and moissanite (2.65) have different refractive indices, which is why they look subtly different from diamond even to an untrained eye. Lab grown and natural diamonds do not.
Price: The Difference That Changes Everything
This is where lab grown and natural diamonds diverge significantly and it's the difference that most buyers find most compelling.
Lab grown diamonds are substantially less expensive than natural diamonds of equivalent quality. The precise discount varies by shape, size, and market conditions, but as a general guide in 2026:
- A lab grown diamond is typically priced 50–80% less than a natural diamond of the same carat weight, cut, colour, and clarity.
- A 1ct G/VS2/Excellent lab grown round brilliant that might cost £2,500–£3,500 at Unii Jewels would cost £8,000–£15,000 as a natural diamond from a comparable retailer.
- The gap widens at larger carat weights. At 2ct and above, lab grown diamonds can be 70–85% cheaper than equivalent natural stones.
Why are lab grown diamonds so much less expensive? Two reasons. First, the supply chain is fundamentally different: a natural diamond takes a billion years to form, requires mining operations on multiple continents, and passes through multiple hands (mine, rough trader, cutter, polisher, wholesaler, retailer) before reaching the consumer. A lab grown diamond is produced in weeks in a controlled facility and has a much shorter route to market.
Second, lab grown diamond production has scaled dramatically over the past decade. As production technology has improved and more facilities have come online globally particularly in India and China the cost of growing diamonds has fallen significantly. That reduction in production cost has flowed through to consumer prices.
What does this mean practically? It means a budget that would buy a 0.7ct natural diamond can buy a 1.5ct lab grown diamond of equivalent quality. For most buyers, that's a significant difference in what they can put on a finger.
Will Lab Grown Diamond Prices Keep Falling?
Probably, yes gradually. Production costs continue to decline as technology improves and more capacity comes online. However, the rate of price decline has slowed considerably from the rapid drops seen in 2020–2023, as the market has matured and retailer pricing has stabilised. The structural cost advantage of lab grown over natural is permanent the production process will always be less expensive than mining but dramatic year-on-year price drops are less likely than they were five years ago.
Resale Value: The Honest Answer
Natural diamonds have historically held resale value better than lab grown diamonds. This is true, and it's worth being honest about.
The resale market for natural diamonds is well-established. Natural diamonds particularly larger, high-quality stones in popular shapes have a secondary market with established pricing. You won't get retail price back (you rarely do with any purchase), but a well-chosen natural diamond can be resold for a meaningful fraction of its original cost.
Lab grown diamonds have a less developed resale market, and resale values have been affected by the ongoing decline in production costs. A lab grown diamond purchased three years ago for £3,000 may have a resale value of £800–£1,200 today, simply because equivalent quality stones can now be purchased for less. This is a real consideration.
However, context matters. The buyer who pays £3,000 for a 1ct lab grown diamond instead of £12,000 for a 1ct natural diamond has £9,000 more in their pocket. Even if the lab grown diamond has a lower resale value in absolute terms, the net financial position of the lab grown buyer is almost always better when you account for the purchase price differential. Resale value matters far more when you're buying a financial asset than when you're buying something to wear and cherish.
The practical reality is that very few engagement rings are ever resold. They're kept, passed down, or reset. Resale value is a legitimate consideration, but it shouldn't dominate the decision for most buyers.
Ethics and Sustainability: A Nuanced Picture
One of the most frequently cited reasons for choosing lab grown diamonds is ethics specifically, avoiding the environmental and human rights issues associated with diamond mining. This is a valid consideration, but the picture is more nuanced than it's sometimes presented.
Natural Diamond Mining
The natural diamond industry has significant environmental impact. Mining operations disturb large areas of land, generate substantial quantities of waste rock, consume large amounts of water and energy, and can have significant effects on local ecosystems. The industry has also historically been associated with human rights abuses conflict diamonds, exploitative labour practices, and unsafe working conditions in some mining regions.
The industry has made genuine progress. The Kimberley Process Certification Scheme, introduced in 2003, attempts to prevent conflict diamonds from entering the market. Major mining companies have made commitments to environmental remediation and worker welfare. Diamonds from countries like Canada, Botswana, and Namibia are produced under relatively strong regulatory frameworks.
But the natural diamond supply chain remains complex and not fully transparent. For buyers with strong ethical concerns, the assurances available are imperfect.
Lab Grown Diamonds
Lab grown diamonds eliminate the mining impact entirely. No land is disturbed, no ecosystems are affected, and the supply chain is short and transparent. However, lab grown diamond production is energy-intensive the CVD and HPHT processes require significant electricity. The carbon footprint of a lab grown diamond depends heavily on the energy source used to power the facility.
Facilities powered by renewable energy (increasingly common) have a very low carbon footprint. Facilities powered by coal (still common in some regions, particularly in China) have a higher footprint. When evaluating a retailer's sustainability claims, it's worth asking about the energy source used in their supply chain.
Overall, most independent environmental assessments find that lab grown diamonds have a substantially lower environmental impact than mined diamonds, even accounting for energy consumption. But "lab grown" is not automatically synonymous with "sustainable" the specifics of the production facility matter.
The Emotional Dimension
This is something that's often left out of lab grown vs natural comparisons, but it's real and worth acknowledging.
Some buyers and some recipients place significant value on the geological story of a natural diamond. The idea that the stone was formed a billion years ago, deep within the earth, and has made its way to a finger in a London or New York jeweller's shop is genuinely meaningful to some people. That meaning is personal and subjective, but it's not trivial.
Others find the provenance of natural diamonds less compelling or actively uncomfortable, given the environmental and ethical complexities of mining. For them, a lab grown diamond doesn't come with baggage; it comes with a clear conscience and a larger stone.
Neither perspective is wrong. The right choice depends on what matters to you and your partner. What we'd encourage is making that choice consciously and deliberately not because of assumptions or social pressure, but because you've considered both options honestly and chosen the one that aligns with your values.
What the Gemological Laboratories Say
Both IGI and GIA have definitively classified lab grown diamonds as diamonds not simulants, not "diamond alternatives", not "synthetic diamonds" in any pejorative sense. GIA's official position is that lab grown diamonds have essentially the same chemical, physical, and optical properties as natural diamonds. IGI grades lab grown diamonds using exactly the same criteria as natural stones.
The Federal Trade Commission (FTC) in the United States updated its jewellery guidelines in 2018 to confirm that lab grown diamonds are diamonds, and that the term "real diamond" applies to both lab grown and natural stones. The only disclosure requirement is that lab grown diamonds must be identified as laboratory grown which IGI certificates do prominently, and which Unii Jewels discloses on every product listing.
Side-by-Side Summary
Here's every meaningful difference and similarity in one place:
- Chemical composition: Identical pure carbon in diamond cubic crystal structure
- Hardness: Identical 10 on the Mohs scale
- Brilliance and fire: Identical same refractive index and dispersion
- Durability: Identical same cleavage properties
- Appearance to the naked eye: Indistinguishable
- IGI/GIA certification: Both available and graded to the same standard
- Price: Lab grown is 50–80% less expensive for equivalent quality
- Resale value: Natural diamonds hold resale value better in absolute terms
- Environmental impact: Lab grown has substantially lower impact in most assessments
- Supply chain transparency: Lab grown is significantly more transparent
- Geological origin: Natural diamonds only lab grown have no geological history
- Distinguishable by specialists: Yes, with specialised spectroscopic equipment only
So Is There Really a Difference?
The honest answer: in terms of what you'll see, feel, and experience wearing the ring every day, no. A lab grown diamond looks identical to a natural diamond of the same quality, feels the same, sparkles the same, and lasts just as long. Your friends, family, and anyone who admires it will never know the difference from looking at it.
The differences that do exist are in origin, price, resale value, and environmental impact. These are real differences but whether they matter, and how much they matter, is entirely personal. For buyers who value maximising the size and quality of stone within a budget, and who aren't concerned with resale, lab grown is an extraordinary choice. For buyers who place value on geological origin or are buying primarily as a long-term investment, natural may be preferable.
What we'd caution against is choosing natural because you assume lab grown is somehow inferior or "fake" it isn't. And we'd equally caution against choosing lab grown simply because it's cheaper without considering whether a natural diamond matters to your partner. Both are real diamonds. The decision should be made with full information, not assumptions.
Shop Lab Grown Diamonds at Unii Jewels
Every diamond at Unii Jewels is IGI certified and laser-inscribed, with full transparency about the growth method, origin, and quality grades. We only stock Excellent cut stones, G–H colour, VS2 or above clarity the same standard we'd apply whether the stone were lab grown or natural.
If you're still deciding between lab grown and natural, our team is available to talk through the options with you before you purchase. There's no pressure we'd rather you make the right decision than the quick one.
