Lab-Grown vs Natural
Both are real diamonds. Both are graded on the same 4C scale by the same gemological laboratories.
The difference is origin — one formed over billions of years underground, the other grown in weeks in a controlled environment.
The visual result is identical. The price is not.
Side-by-Side Summary
Lab-Grown Diamond
Chemical composition100% carbon
Crystal structureCubic (identical)
Hardness (Mohs)10
CertificationIGI, GIA
Price vs natural60–85% less
Resale valueLower, declining
Laser inscriptionReport no. + "LG"
Time to formWeeks to months
Natural Diamond
Chemical composition100% carbon
Crystal structureCubic (identical)
Hardness (Mohs)10
CertificationGIA, IGI
Price premium5–10× lab equivalent
Resale valueBetter, more stable
Laser inscriptionReport number only
Time to form1–3 billion years
Spada's position: We source both lab-grown and natural diamonds. We specialise in lab-grown because the value proposition for retail jewellers is unmatched — your customer gets a larger, higher-quality stone at the same price point. We'll always tell you which is which and recommend based on your brief.
The Honest Answer
A lab diamond is not a "fake" diamond, a simulant, or cubic zirconia. It is a diamond. The only meaningful differences are where it came from, what it costs, and what it might be worth if resold. Use the panels in this guide to understand each difference in full.
What's Identical
Lab-grown and natural diamonds share the same chemical formula, the same crystal structure, and the same physical and optical properties. No gemologist can distinguish them with a loupe or microscope — specialist equipment is required.
Chemical & Physical Properties
| Property | Lab-Grown | Natural |
|---|
| Chemical formula | C (pure carbon) | C (pure carbon) |
| Crystal system | Cubic | Cubic |
| Mohs hardness | 10 | 10 |
| Density | 3.51–3.53 g/cm³ | 3.51–3.53 g/cm³ |
| Refractive index | 2.417 | 2.417 |
| Dispersion | 0.044 | 0.044 |
| Thermal conductivity | Highest of any material | Highest of any material |
| Scratch resistance | Identical | Identical |
What This Means Practically
To the Naked Eye
Completely indistinguishable. No human — including expert gemologists — can tell a lab diamond from a natural diamond by looking at it.
Under a Loupe (10×)
Still indistinguishable by inclusions alone. Both have internal characteristics — the type and pattern differ but cannot be used to identify origin without specialist testing.
Thermal Testing
Diamond testers that measure thermal conductivity will register both lab and natural stones as diamond — they cannot distinguish between them. Moissanite testers also apply equally.
Detection Equipment
Specialist instruments (GCAL DiamondCheck, De Beers SYNTHdetect, GIA iD100) use UV fluorescence and photoluminescence spectroscopy to identify lab origin. These are lab-grade instruments — not available in most retail environments.
Laser Inscription
IGI lab-grown diamonds are laser-inscribed on the girdle with their report number and "LG" or "LAB GROWN." This is the practical identifier — not a detectable physical property.
Durability in Use
Identical. A lab diamond set in a ring will wear, scratch-resist and survive exactly like a natural diamond. No difference in setting security, daily wear, or longevity.
Trade Note
When a customer asks "but can you tell the difference?" — the honest answer is no, not without specialist laboratory equipment. A lab diamond and a natural diamond in the same setting, to the same person across a table, are visually identical. The difference is on the certificate, not in the stone.
How They're Made
Natural diamonds formed deep in the earth under extreme conditions over billions of years.
Lab diamonds replicate those conditions — one in weeks using gas, the other in days using pressure.
The end result is the same crystal structure.
Natural Diamond Formation
Where
150–200km below the earth's surface, in the mantle layer — far deeper than any mine can reach.
Conditions
Extreme heat (900–1,300°C) and pressure (45–60 kilobars) over millions to billions of years crystallise carbon into diamond.
How It Reaches the Surface
Volcanic eruptions carry diamonds to the surface via kimberlite pipes — rare, carrot-shaped columns of rock. Most kimberlite pipes contain no diamonds.
Age
Most gem diamonds are 1–3 billion years old. Some are as old as 3.5 billion years — older than most life on Earth.
CVD — Chemical Vapour Deposition
Most common method for white lab diamonds. A thin diamond seed crystal is placed in a vacuum chamber. A carbon-rich gas (typically methane) is superheated into a plasma. Carbon atoms break free and deposit onto the seed crystal, building the diamond atom by atom, layer by layer. Growth takes 2–4 weeks. The resulting rough crystal is then cut and polished identically to mined rough.
- CVD diamonds sometimes develop a brown or greyish tint during growth caused by structural strain. Post-growth HPHT treatment can remove this and improve colour — this is a common and fully disclosed process.
- CVD is the preferred method for producing large, high-quality colourless diamonds. Most D–H colour lab diamonds in the market are CVD.
- The seed crystal used in CVD is itself a diamond — either natural or lab-grown. The process is self-sustaining once commercial production is established.
HPHT — High Pressure High Temperature
Mimics earth conditions directly. A diamond seed crystal and carbon source are placed in a specialised press. The press applies approximately 60,000 atmospheres of pressure and temperatures of 1,300–1,600°C — replicating the conditions deep in the mantle. Carbon melts and crystallises onto the seed over days to weeks. More energy-intensive than CVD but produces very consistent results.
- HPHT is also used to treat natural and lab diamonds after growth — improving colour grade by removing nitrogen and other impurities. This treatment must be disclosed on the certificate.
- Fancy coloured lab diamonds (yellow, orange, blue) are more commonly produced by HPHT, where specific trace elements can be introduced to create colour.
- HPHT-grown diamonds tend to produce a distinctive octahedral crystal shape — the same shape natural diamonds form in the earth.
Trade Note
For most retail enquiries, the growth method (CVD vs HPHT) is less relevant than the final grade. What matters is the IGI report — cut, colour, clarity, and carat. If a customer asks which method their stone used, it's disclosed on the IGI certificate.
The Price Difference
The price gap between lab-grown and natural diamonds has widened dramatically since 2020.
Lab diamonds now typically sell at 60–85% below natural equivalents at the same grade.
For retail jewellers, this means a fundamentally different value proposition for customers.
Same Budget — What You Get
Lab-Grown · $5,000 AUD
2.00ct Round Brilliant
F colour · VS1 clarity
Excellent cut · Triple EX
IGI certified
~$5,000 AUD wholesale
Natural · $5,000 AUD
0.70ct Round Brilliant
H colour · VS2 clarity
Very Good cut
GIA certified
~$5,000 AUD wholesale
Price Gap by Carat Weight (approx. wholesale)
0.50ct H/VS2
Lab ~20% of nat.
1.00ct G/VS1
Lab ~18% of nat.
1.50ct F/VS1
Lab ~15% of nat.
2.00ct E/VVS2
Lab ~13% of nat.
3.00ct D/VS1
Lab ~10% of nat.
Bars show lab price as a percentage of natural equivalent. Gap widens at larger carat weights. Prices are indicative — contact Spada for current pricing.
Why the Gap Exists
Supply
Lab diamond production has scaled rapidly since 2018. Supply is essentially unlimited — any carat weight and quality can be produced to order. Natural supply is fixed by geology.
Cost to Produce
CVD production costs have fallen dramatically as technology improved. A 1ct lab diamond that cost $4,000 to produce in 2015 costs under $300 today.
Natural Price Stability
Natural diamond prices have remained relatively stable — controlled supply from major mining companies (De Beers, Alrosa) maintains market price floors.
Lab Price Trajectory
Lab prices have fallen 70–80% since 2020 and continue to decline. The gap between lab and natural is likely to widen further, not narrow.
Trade Note
The price gap creates a retail opportunity: your customer's budget goes further, your margin is maintained (or improved), and the stone they receive is objectively higher grade than what natural would deliver at the same spend. Lead with quality, not price reduction — "more diamond for the same budget" lands better than "cheaper diamonds."
The 4Cs — Lab vs Natural
IGI and GIA grade lab-grown diamonds on the same 4C scale as natural diamonds.
The grades mean exactly the same thing. Where lab-grown has a practical advantage is in availability
— top grades that are exceptionally rare in natural diamonds are common and affordable in lab.
Where Lab-Grown Has an Edge
| C | Lab-Grown | Natural | Practical Difference |
|---|
| Cut |
Identical grades |
Identical grades |
No difference. Both graded Excellent → Poor by the same standards. |
| Colour |
D–F common, affordable |
D–F rare, expensive |
A D colour lab costs a fraction of a D colour natural. Customers can afford colourless grades that would be out of reach in natural. |
| Clarity |
VVS/VS very common |
VVS/FL rare premium |
VS1 and VVS2 are everyday grades in lab. FL and IF lab stones exist at reasonable cost — in natural, these are exceptional and extremely expensive. |
| Carat |
Any size, to order |
Large sizes very scarce |
2ct+ lab diamonds are routinely available. Natural 2ct+ stones in top grades are rare and carry significant premiums. 3ct+ natural stones are exceptional. |
Grading Consistency
- IGI is the world's largest grader of lab-grown diamonds. Their 4C grades for lab stones are assessed by the same gemologists using the same tools as natural stones.
- IGI is known to grade slightly more liberally than GIA for both natural and lab diamonds. A GIA G might be an IGI F. This applies equally to both origin types — it's a lab policy difference, not a lab vs natural difference.
- All Spada stones carry IGI reports. If a customer requires GIA certification on a natural stone, this can be arranged — note that GIA-graded natural stones carry a price premium reflecting the stricter grading standard.
- Lab-grown diamonds also carry a distinct "Laboratory-Grown" notation on IGI reports, plus the growth method (CVD/HPHT) — full disclosure is standard and mandatory.
The practical upgrade: A customer with a $3,000 budget who would receive an H/SI1 in natural can receive an E/VVS1 in lab. Both are IGI-certified. Both are Excellent cut. One is objectively higher grade. The only difference is origin and future resale value.
Trade Note
When presenting both options to a customer, use the same grade comparison — show them what $X buys in natural vs lab at equivalent quality. The upgrade in size or grade speaks for itself. Let them choose origin; you've done your job by showing the full picture.
Ethics & Origin
The ethical comparison between lab and natural diamonds is more nuanced than marketing from either side suggests.
Neither is definitively "cleaner" — but lab avoids mining entirely, which removes several categories of concern.
Here is the honest picture.
Natural Diamond Mining
Land Disturbance
Open-pit and underground mines disturb significant land area. The Jwaneng mine in Botswana — one of the world's largest — covers several square kilometres.
Carbon Footprint
Estimates vary widely by mine. Rough figures suggest 160kg of CO₂ per polished carat from large-scale mining operations, but this figure is disputed and varies enormously by source.
Community Impact
Mining provides significant employment in producer countries (Botswana, Canada, Russia, Australia). Many communities are economically dependent on diamond mines.
Conflict Diamonds
The Kimberley Process Certification Scheme (KPCS) was introduced in 2003 to prevent conflict diamonds entering the supply chain. It covers roughly 99% of global rough production but has known limitations in definition scope.
Lab Diamond Production
No Mining
Lab diamonds require no land disturbance, no habitat destruction, and no tailings ponds. The physical footprint of a lab is a fraction of a mine.
Energy Use
CVD and HPHT are energy-intensive. Estimates range from 250–750 kWh per carat depending on the reactor and efficiency. The carbon footprint depends heavily on whether the facility uses renewable energy.
Renewable-Powered Labs
Some lab producers (notably in the US and Europe) run on renewable energy, making their carbon footprint very low. Indian and Chinese producers, who dominate volume, rely more heavily on grid power.
Traceability
Lab diamonds have complete, verifiable traceability — from the growth facility to the polisher to the retailer. There is no supply chain opacity equivalent to artisanal alluvial mining.
The honest comparison: A lab diamond from a renewable-energy facility is significantly lower carbon than a mined diamond. A lab diamond from a coal-powered facility in India is less clear-cut. The environmental case for lab is strongest when the energy source is verified. The case for avoiding conflict diamonds is absolute — lab has no conflict diamond risk by definition.
- The Kimberley Process defines "conflict diamonds" narrowly as stones financing rebel movements against recognised governments. Human rights organisations have noted this excludes diamonds from authoritarian regimes or mines with poor labour conditions.
- Canadian and Australian-mined diamonds carry strong traceability credentials and strict environmental standards — among the most responsibly sourced naturals available.
- Lab diamond facilities can be independently audited for energy use and labour practices in ways that underground mines cannot.
Trade Note
When customers raise ethics as a reason to choose lab, affirm it — lab does remove mining from the equation entirely. Don't oversimplify to "lab is green" without qualifying energy source. The nuanced answer builds more trust than a marketing headline.
Resale Value
This is the area where lab and natural diverge most significantly.
Natural diamonds have historically retained value better. Lab diamond resale values have declined sharply as production scaled.
Neither is a reliable investment — but natural holds its ground far better than lab if resale matters to the customer.
Lab-Grown Resale Reality
Lab diamonds have lost significant resale value since 2020. A 1ct lab diamond that retailed for $3,000 in 2021 may resell for $200–400 today, as market prices have fallen dramatically. Second-hand lab diamonds compete with new lab diamonds that are now cheaper than ever. The resale market for lab is thin and declining.
- Lab diamonds are not recommended as financial investments. If a customer is thinking "I can always sell it," they should be advised honestly that lab resale value has eroded substantially.
- The resale decline reflects supply dynamics, not a quality issue — the stone is as beautiful and durable as ever, but the replacement cost has dropped below what was paid.
- For insurance purposes, lab diamonds should still be insured at replacement cost (what a new equivalent would cost today), not at original purchase price.
Natural Diamond Resale
Natural diamonds retain value significantly better than lab. A quality natural diamond (1ct+, high colour and clarity, reputable cert) typically resells at 30–50% of retail. This is not spectacular — but it is far better than lab. Large, high-quality natural diamonds (3ct+, D/IF) in top grades can appreciate over time as supply from mining diminishes.
- Even natural diamonds are not reliable investments at the retail level. The spread between retail price and resale value is significant — typically 40–60% loss on immediate resale.
- Investment-grade natural diamonds (5ct+, exceptional quality, major auction houses) behave differently and can appreciate. This is not the typical retail customer's situation.
- The best reason to buy either type is meaning and enjoyment, not financial return. Be honest with customers about resale expectations for both.
Lab: Short-Term Resale
Typically 5–15% of original retail in the current market. Declining as new production continues to reduce replacement costs.
Natural: Short-Term Resale
Typically 30–50% of original retail. More stable — natural supply is fixed and market pricing is more controlled.
Insurance
Insure both at current replacement cost. For lab, this may now be lower than the original purchase price. Update valuations every 2–3 years.
Upgrade Programmes
Some retailers offer trade-in or upgrade programmes for lab diamonds at a fraction of original value. Natural diamonds generally trade in at better rates through jewellers.
Trade Note
If a customer raises resale value as a deciding factor, be straight: natural retains value better. If their primary goal is financial return, natural is the more defensible choice. If their goal is the most beautiful stone for their budget, lab wins clearly. Frame it as two different priorities, not two versions of the same product.
Which to Choose
There is no universally correct answer. The right choice depends on what the customer values most.
Use this decision framework to guide the conversation — and then let them decide.
Decision Framework
Budget is the main constraint — they want as much stone as possible
Lab-Grown
Clear advantage. Same budget buys 3–5× more carat weight or a significantly higher grade. The better stone for the money, objectively.
Natural
Limits carat weight and grade significantly at the same spend. Correct choice only if origin is the priority.
They want the largest, most impressive ring possible
Lab-Grown
Clear advantage. A 2ct lab is achievable at a budget where natural delivers 0.70ct. Visual impact is entirely in favour of lab.
Natural
Significantly limits what size is achievable. The stone will be real — but smaller.
Resale value or long-term investment matters to them
Lab-Grown
Not recommended for investment. Resale value has declined sharply. Buy lab for beauty, not financial return.
Natural
Better resale retention — typically 30–50% of retail. Not an investment, but holds ground far better than lab.
Ethics and origin are important to them
Lab-Grown
No mining, full traceability, no conflict diamond risk. Environmental impact depends on energy source — ask the supplier.
Natural
Kimberley Process covers most supply. Canadian/Australian stones offer strongest ethical credentials. Community employment is a positive impact in producer countries.
Tradition, sentiment, or the geological origin story matters
Lab-Grown
No geological story. Grown in weeks. For some customers, this diminishes the romance — respect that.
Natural
Formed over billions of years. Genuinely rare. The origin story resonates with many customers, especially for engagement rings.
They want the highest possible quality grade
Lab-Grown
D/IF/Triple EX is available at reasonable cost. Top grades are accessible for any budget.
Natural
D/IF/Triple EX natural is exceptionally rare and extremely expensive. Usually beyond reach except at very high budgets.
The bottom line: Lab wins on price, size, quality-per-dollar, and traceability. Natural wins on resale value and geological origin. Neither is a financial investment. Both are real diamonds. Let the customer's priorities guide the decision — your job is to make sure they understand the full picture before they choose.
From Spada Jewellers, Melbourne
We source both lab and natural. When you submit a brief, tell us which the customer prefers — or if they're undecided, we'll quote both and let the comparison make the case. We source and deliver within 7 business days, fully IGI certified, with a clear recommendation based on your customer's priorities.
