Same carbon, same crystal, same hardness. The differences that matter are somewhere else entirely.

Let's settle the first question immediately: a lab-grown diamond is a real diamond. Same carbon, same crystal structure, same 10 on the Mohs scale. A gemologist cannot tell the difference by eye — it takes specialized equipment reading trace elements and growth patterns.

Anyone who tells you lab-grown diamonds are "fake" is either misinformed or selling something. The real differences are elsewhere, and they matter.

One disclosure up front: ISAAC WESTMAN does not currently offer lab-grown diamonds — our collection is natural stones. We have written this guide anyway, because you deserve the full picture before you spend, and a comparison is not much use if the person writing it pretends the alternative has no merits.

How each one forms

Natural diamonds formed one to three billion years ago, roughly 100 miles below the surface, under heat and pressure, and were carried up by volcanic activity.

Lab-grown diamonds are made in weeks using one of two methods: High Pressure High Temperature (HPHT), which reproduces those conditions mechanically, or Chemical Vapor Deposition (CVD), which builds the crystal layer by layer from carbon gas.

The output is chemically identical. The inputs are time and origin.

Price — the real difference

This is why most people are reading this. Lab-grown diamonds cost dramatically less than natural stones of equivalent size and quality. The gap has widened as production has scaled.

Practically, that means at a given budget you can choose:

• A smaller natural stone, or
• A considerably larger lab-grown stone at the same clarity and color

Neither answer is wrong. It depends on what you want the ring to be.

One piece of context worth knowing: lab-grown prices fell steeply for several years as supply expanded, then flattened. The "wait and it'll be cheaper" era appears to have ended.

On what to spend either way, see how much should an engagement ring cost.

Resale — be realistic about this

Here is where we will be blunter than most.

Natural diamonds hold resale value better than lab-grown — because supply is finite and the secondary market is established. Lab-grown diamonds have minimal resale value, because supply is effectively unlimited and new production keeps getting cheaper.

But read that carefully, because the honest framing matters: neither is an investment. A natural diamond bought at retail and sold secondhand typically returns a fraction of what you paid. Anyone selling you a diamond as a financial asset is misrepresenting it — and yes, that applies to us too.

The useful version of the question is not "which appreciates" — neither does. It is "if this piece is passed down or traded up in twenty years, does that matter to me?" For heirloom intent, natural has the edge. For a beautiful ring you intend to wear and keep, the distinction is largely academic.

Certification — insist on it either way

This is the part that changed recently, and it is worth getting right.

For natural diamonds, both GIA and IGI issue full 4Cs reports. GIA created the 4Cs and the D-to-Z color scale, and is regarded across the trade as the strictest and most consistent laboratory — the benchmark everyone else is measured against.

For lab-grown diamonds, the two laboratories no longer do the same thing. Since October 1, 2025, GIA has stopped applying 4Cs nomenclature to laboratory-grown stones. Rather than a color and clarity grade, it issues a Laboratory-Grown Diamond Quality Assessment classifying a qualifying stone as Premium or Standard. The reasoning is that the overwhelming majority of lab-grown diamonds now cluster in a very narrow band of high color and clarity, so the fine distinctions stopped distinguishing anything.

IGI continues to issue 4Cs-style reports for lab-grown diamonds, and grades the majority of them.

The practical consequence: you cannot directly compare a GIA lab-grown assessment against an IGI lab-grown report. They are different systems. Compare within one laboratory, or ask the seller to explain the difference.

Two rules either way:

1. Get a report from an independent lab — not an in-house "appraisal" from the seller.
2. Verify the report number on the lab's own website. Reports are public and searchable.

Lab-grown stones are typically laser-inscribed on the girdle with both the report number and an indication that they are laboratory-grown. That inscription is a feature, not a stigma — it means the stone's identity travels with it.

The environmental argument, honestly

Lab-grown is frequently marketed as the ethical choice. The reality is more mixed than either side admits.

Growing diamonds is energy-intensive, and the footprint depends heavily on the electricity source — a stone grown on renewable power and one grown on coal are not comparable. Mining has real land and water impacts, but it also supports livelihoods in producing countries, and the industry's traceability has improved substantially.

If this matters to you, the useful move is to ask specific questions — about energy sourcing for lab stones, about origin and chain of custody for natural ones — rather than accept a category-level claim from either direction.

Who should choose which

Lab-grown makes sense if size at your budget is the priority, you want a larger stone for studs or a tennis bracelet without a five-figure spend, you are untroubled by resale, or you simply like that it was made rather than mined.

Natural makes sense if the geological origin matters to you, you are buying with heirloom intent, you want the stronger secondary market, or you value the rarity itself as part of the meaning.

There is no wrong answer here. There is only the answer you will be glad of in ten years — and for most people, that has more to do with how the ring was chosen than with which category the stone came from.

Where we stand

We have been sourcing diamonds through cutters in the major diamond centers since the early 1980s. Those relationships are built around natural stones, and that is what our collection is today. It is not a judgment on lab-grown — it is simply what four decades of supply relationships produced.

Our house standard is the same on every stone: VS2 clarity or better, H–I color or better, Excellent or Very Good cut, and independent certification on every center stone of 1.00 carat and above.

If lab-grown is right for your budget and your priorities, buy it with confidence — just insist on independent certification, and go in knowing the resale reality. If natural is what you are after, we would be glad to help.

Reach us at sales@isaacwestman.com or 1-347-389-0766, or start with our guide to the 4Cs. On the metal, see 14K vs 18K gold vs platinum. Browse engagement rings and diamond jewelry.

Heirlooms in the making.

ISAAC WESTMAN® · New York · Founded 1982