TL;DR

Lab-grown and natural diamonds are chemically identical — both are pure carbon, both score 10 on the Mohs hardness scale, and both look the same to the naked eye. The real difference is origin and price: a lab-grown diamond costs roughly 60–80% less than a natural diamond of the same 4Cs, but it also holds far less resale value. If you want maximum carat for your budget, go lab-grown. If you want a long-term store of value or a family heirloom, go natural. We sell both at Bijouterie Jamil and we will tell you honestly which one fits your situation.

What a diamond actually is (and why "lab-grown" is not "fake")

A diamond is crystallized carbon. That is the entire scientific definition. Whether the crystal grew over a billion years deep in the earth or over a few weeks inside a high-pressure reactor in a lab, the finished stone is the same material with the same hardness, the same refractive index, and the same fire.

This is the part most people get wrong. A lab-grown diamond is not a cubic zirconia and it is not moissanite. Cubic zirconia is zirconium oxide — a totally different material that scratches and clouds within a year or two. Moissanite is silicon carbide — a separate gemstone that has more rainbow flash than a diamond and can be told apart by a trained eye. A lab-grown diamond is a diamond. Even a gemmologist cannot tell one from a natural diamond without specialized equipment.

If a customer brings us a stone and asks whether it is a real diamond, we test it on a thermal probe and, if needed, on a Type IIa screening device. That tells us "diamond, yes" or "diamond, no." To tell lab from natural we need a deeper test — and that is exactly what GIA and IGI do when they certify a stone.

How lab-grown diamonds are actually made

There are two methods. HPHT (High Pressure High Temperature) recreates the conditions deep in the earth's mantle: a small diamond seed is placed in a press at around 1,500 °C and 5–6 gigapascals of pressure, surrounded by a carbon source. CVD (Chemical Vapour Deposition) uses a vacuum chamber filled with methane gas; the carbon atoms separate from the methane and deposit, layer by layer, on a diamond seed plate.

Both methods produce a rough crystal that is then cut and polished by the same diamond cutters who work with natural rough. Most of the lab-grown diamonds we sell at Bijouterie Jamil are CVD, because the colour grades are slightly more consistent in the D–F range.

The whole process takes 2–4 weeks for a 1-carat stone. A natural diamond of the same size took 1 to 3 billion years to form and was then mined out of the earth. That time difference is the entire reason for the price gap.

The price difference — real 2026 numbers

Here is what a 1.00 ct round brilliant, F colour, VS1 clarity, Excellent cut actually costs in Montréal in 2026:

• Natural, GIA certified: $7,500–$9,500 CAD for the loose stone
• Lab-grown, IGI certified: $1,400–$2,100 CAD for the loose stone

For the same setting (a simple 14K white gold solitaire, around $850 CAD), the finished ring lands at roughly $8,500–$10,500 CAD natural versus $2,400–$3,200 CAD lab-grown. That is a 65–75% saving — and the visual stone in the prongs is identical.

Move up to a 2.00 ct of the same specs and the gap widens. Natural runs $22,000–$32,000 CAD. Lab-grown runs $3,500–$5,500 CAD. That is the bracket where most clients who choose lab-grown make the call: they get a visibly larger stone for less than the price of a 1 ct natural.

Prices on lab-grown have dropped roughly 70% since 2020. They will likely keep drifting lower as production capacity grows. Natural diamond prices have stayed relatively stable, with a slight 2024–2025 dip that has now levelled off.

Resale value — the honest tradeoff

This is where we have to be straight with you. A natural diamond of decent quality (G colour or better, VS clarity or better, GIA report) holds 30–50% of its retail value at resale through a jeweller, and sometimes more at auction for sizes above 2 ct. A lab-grown diamond of the same specs currently holds 0–20% at resale. Some buyers will not take them at all yet.

Why? Because the supply of lab-grown is effectively unlimited. A natural diamond is finite — the deposit in the earth is what it is. A lab can produce another identical stone next month for less than this month's production cost. The market knows that, and resale prices reflect it.

So the rule we give clients is simple. If the diamond is going to stay in the family — passed to a daughter, kept as a milestone piece, eventually inherited — natural makes more financial sense over a 30–50 year horizon. If the diamond is for the moment, the wedding, the day, and resale is not part of the plan, lab-grown gives you dramatically more carat per dollar.

Certification — what to actually look for

Both lab-grown and natural diamonds should come with a grading report from an independent lab. The two reports we trust at Bijouterie Jamil are GIA (Gemological Institute of America) and IGI (International Gemological Institute). A third, AGS, was absorbed by GIA a few years back and its older reports are still valid.

For natural diamonds, GIA is the gold standard. For lab-grown, IGI dominates the market — they were the first major lab to grade them at scale and most lab-grown stones in 2026 ship with an IGI report.

A real grading report will state, in clear language: - The stone's origin: "natural" or "laboratory-grown" - Carat weight to the second decimal - Colour grade (D–Z) - Clarity grade (FL to I3) - Cut grade (Excellent, Very Good, Good, Fair, Poor) - Measurements in mm - A unique report number that you can verify on the lab's website

If you have a report number, go to gia.edu/report-check or igi.org/verify-your-report and type it in. The actual certificate should match what is on the lab's database. If it does not, the report is fake — bring the stone to us or to any reputable jeweller and we will test it for free.

For stones over 0.30 ct, most GIA and IGI reports also include a laser-inscribed report number on the diamond's girdle, visible under 10x magnification. We check this at our bench whenever we set a customer's stone, and we recommend you ask your jeweller to do the same on delivery.

Looking for a deeper walkthrough on grading? Our guide on the 4Cs and how diamonds are graded explains colour, clarity, cut, and carat in plain language.

How we verify authenticity at the bench

When a customer walks in with a ring and asks "is this real," here is the actual process we run, in the order we run it:

1. Visual check under 10x loupe — we look for telltale signs of cubic zirconia (rounded facet edges, internal bubbles) or moissanite (doubling of facet edges).
2. Thermal conductivity probe — separates diamond and moissanite from everything else in about 5 seconds.
3. Diamond/moissanite tester — a second probe that uses electrical conductivity to separate diamond from moissanite specifically.
4. Type IIa screening device — for stones over 0.20 ct, this flags whether a stone might be lab-grown or treated. If it flags, we recommend sending the stone to GIA or IGI for a full report.
5. Cross-check the laser inscription against the report number on file.

The whole process at our Montréal store takes about 10–15 minutes for a single stone and we do not charge for it on stones we sold or on stones a regular client brings in for peace of mind. For estate pieces or unknown provenance, we charge $50 CAD for a written authentication and $150–$300 CAD for a full appraisal with a signed valuation document — useful for insurance.

If you bought a diamond online or inherited a piece and you want it checked, just bring it in. We will tell you what it is, on the spot, in plain language. No pressure to buy anything.

So which one should you choose?

We do not have a "right answer" — we have a framework.

• Choose lab-grown if: your budget is fixed and you want the biggest, cleanest visible stone for the money; you do not see this piece as a long-term financial asset; you like the idea of a stone with a known, traceable origin (no mining concerns).
• Choose natural if: you want the piece to hold meaningful resale value over decades; the stone will likely be inherited; you value the geological backstory and the scarcity it represents.
• Choose either with confidence if: the report comes from GIA or IGI, the report number verifies on the lab's website, and the jeweller can show you the laser inscription on the stone.

Either way, the engagement ring lasts. Diamond is the hardest natural material on earth and the hardest lab-made material we make in volume. With basic care (off when you wash dishes, cleaned every 6 months, prongs checked annually), a well-set diamond ring will outlast most marriages. We see rings from the 1950s come into our jewellery repair workshop every week that just need a polish and a prong tightening to look new.

A soft note before you decide

Come in and see both. We keep loose lab-grown and natural diamonds in the same drawer at our Montréal store, in matching specs, so clients can hold them up under the same light and decide what their eye prefers. Most people are surprised that they cannot tell the difference. A few are surprised that they can — and almost always go natural after that. There is no wrong choice, only the choice that fits your situation.

If you would like a quote on a specific carat and quality, book a no-pressure consultation or stop by the store. We will pull the stones, walk through the reports, and give you real numbers in writing.

Frequently Asked Questions

Are lab-grown diamonds real diamonds? Yes. Lab-grown diamonds are chemically, optically, and physically identical to natural diamonds — both are pure crystallized carbon, both rate 10 on the Mohs scale, and both refract light the same way. They are not cubic zirconia and not moissanite. The only difference is origin: one grew in the earth, the other grew in a reactor.

How much cheaper are lab-grown diamonds in 2026? For a 1.00 ct round F/VS1 Excellent cut, expect roughly $1,400–$2,100 CAD lab-grown versus $7,500–$9,500 CAD natural in Montréal. That is a 65–80% discount for visually identical stones. The gap widens as the carat weight increases.

Do lab-grown diamonds hold their value? Generally no. Current resale value on lab-grown sits between 0 and 20% of retail, because supply is effectively unlimited. Natural diamonds of GIA-certified quality typically retain 30–50% of retail at resale and sometimes more for stones above 2 ct.

What is the difference between GIA and IGI certificates? GIA (Gemological Institute of America) is the most respected lab for natural diamonds. IGI (International Gemological Institute) dominates lab-grown diamond grading and is also reputable for natural stones. Both are independent, both are accepted in the trade, and both let you verify any report number on their website.

How can I tell if my diamond is real or fake? Bring it to a jeweller with proper testing equipment. A thermal conductivity probe takes 5 seconds and rules out cubic zirconia. A second tester separates moissanite from diamond. For lab-grown vs natural, you need a Type IIa screener or a full lab report. We do this check for free in our Montréal store.

Is the certification paperwork included when I buy a diamond from Bijouterie Jamil? Yes. Every certified diamond we sell ships with its original GIA or IGI report. We also provide a written appraisal for insurance on request, and we can show you the laser-inscribed report number on the stone's girdle under our bench loupe before you take the ring home.

Can a jeweller tell a lab-grown diamond from a natural one just by looking at it? No, not reliably. Even an experienced gemmologist needs a Type IIa screening device or a full lab analysis to be sure. Anyone who claims they can spot a lab-grown by eye is bluffing. This is exactly why the certification report matters.

Are lab-grown diamonds a good choice for an engagement ring? Yes, if you understand the tradeoff. You will get a much bigger or cleaner stone for the same budget, and it will look identical to a natural diamond on her finger. Just go in knowing the resale value is low and that your reason for choosing it is "more stone today" rather than "long-term asset."

About the author Nader Khazzoum is co-owner and master jeweller at Bijouterie Jamil in Montréal, the family's second-generation shop opened in 1962. He specializes in custom fabrication, diamond setting, and laser welding, and personally inspects every stone that goes into a ring made at the bench. Bijouterie Jamil is independent, family-run, and serves clients across Québec in French and English.