Natural vs Lab-Grown Gemstones
A lab-grown gem is not a fake. It is the same mineral, grown in weeks instead of eons — and priced accordingly. Here is what really separates the two.
Few phrases cause more confusion at the jewellery counter than “lab-grown.” Some buyers hear it as a polite word for fake; others assume it means a cheap imitation like glass. Both are wrong. A lab-grown, or synthetic, gemstone has essentially the same chemical composition, crystal structure and optical properties as its natural counterpart. Under a loupe it looks like the real thing because, mineralogically, it is the real thing — simply made by people rather than by geology.
That single fact reshapes everything about value. The reason a fine natural ruby costs what it does is scarcity: the right chemistry, heat and pressure had to meet in the earth and survive to the surface. A laboratory removes the scarcity, so it removes most of the price. Understanding the vocabulary is the first defence against paying natural prices for grown material, or vice versa.
Three words that are not the same thing
Precision matters here, because the trade uses these terms carefully and so should you.
Natural
Formed in the earth without human intervention in its crystallisation. It may still be treated — heated, oiled, irradiated — but its birth was geological.
Synthetic (lab-grown, lab-created)
Grown in a laboratory but with the same composition and structure as the natural mineral. A lab-grown sapphire is corundum, exactly like a mined sapphire. “Created” and “cultured” are marketing words for the same thing and must be qualified so buyers are not misled.
Imitation (simulant)
Looks like a gem but is a different material entirely. Cubic zirconia and glass imitate diamond; moissanite (silicon carbide) is its own material sold as a diamond alternative. A simulant is neither natural nor synthetic version of the stone it mimics — it is something else that resembles it.
How lab gems are actually made
There is no single method. Coloured stones such as ruby, sapphire and spinel have been grown since 1902 by flame fusion (the Verneuil process), which drips powdered feed through a flame onto a growing boule — fast and inexpensive. Finer synthetics use the slower flux and hydrothermal methods, which better mimic natural growth and are common for lab emerald. Lab-grown diamonds are made two ways: HPHT (high pressure, high temperature), which recreates deep-earth conditions, and CVD (chemical vapour deposition), which builds diamond layer by layer from a carbon-rich gas. The method leaves clues — and those clues are how gemmologists tell grown from natural.
How the two are told apart
Usually not with the naked eye. Because the material is the same, separation relies on tiny growth features that only a trained gemmologist or a laboratory can read. Flame-fusion synthetics often show curved growth lines, where natural stones show straight, angular zoning. Flux-grown stones can trap wisps or droplets of the flux. Lab diamonds may carry metallic inclusions (HPHT) or particular strain and fluorescence patterns (CVD) revealed by specialist instruments. For anything of real value, a report from a recognised laboratory is the only reliable answer.
What it means for value
| Category | What it is | Relative value |
|---|---|---|
| Natural, untreated | Earth-formed, no enhancement | Highest; scarcity plus purity command a premium |
| Natural, treated | Earth-formed, then enhanced | Lower than untreated; still a natural stone |
| Synthetic (lab-grown) | Same mineral, made in a lab | A fraction of natural; lab diamonds have fallen sharply |
| Simulant | Different material, similar look | Lowest; priced as its own inexpensive material |
Lab-grown stones are not “worse” — they are often cleaner and more affordable, and for many buyers that is exactly the appeal. What they should never be is undisclosed. If value retention or rarity matters to you, that points toward natural; if beauty per pound matters most, lab-grown is a rational, honest choice. Neither answer is universally correct, and we do not offer investment advice — only the facts to choose with open eyes.
Watch-outs
- Undisclosed synthetics. The core risk is a lab-grown stone sold at natural prices. Reputable sellers state it plainly; vague listings that avoid the words “natural” or “lab-grown” deserve a direct question.
- “Created,” “cultured,” “grown” without context. These all mean synthetic. They are legitimate only when the listing makes clear the stone is lab-made.
- Simulant sold as the real stone. Cubic zirconia or glass described loosely as “diamond” is a different problem from synthetics — it is not the mineral at all. Ask for the exact material.
- Assuming lab means valueless, or natural means untreated. A lab stone is genuine mineral; a natural stone may still be heavily treated. Two separate questions — ask both.
Whichever you choose, insist on plain words: natural or lab-grown, treated or not.
Lab-grown gems are honest value when sold as what they are. The only way to overpay is to be handed a synthetic, or a simulant, at natural prices — so ask, and get it in writing for anything of value.
Browse natural gemstones at Minerals Kingdom →FAQ
Is a lab-grown gemstone fake?
No. A lab-grown gem has the same chemical composition and crystal structure as the natural mineral, so it is genuinely that gem — a lab sapphire is real corundum. “Fake” better describes a simulant such as cubic zirconia, which only imitates the look with a different material.
Can I tell natural from lab-grown at home?
Rarely. Because the material is identical, separation depends on microscopic growth features and instrument tests that require a gemmologist. For any stone of value, a report from a recognised laboratory is the dependable way to know.
Why are lab-grown diamonds so much cheaper now?
Production has scaled up and improved, so supply is plentiful and prices have fallen substantially through the 2020s. A natural diamond’s price still rests on geological scarcity, which a laboratory does not share.
Do lab-grown stones need disclosure?
Yes. Selling a synthetic without clearly disclosing it is misrepresentation. Honest listings use words like “lab-grown” or “synthetic” and, ideally, back higher-value stones with a laboratory report.
More value guides
Sources
GIA and general gemmological literature — definitions of natural, synthetic and imitation gemstones; the Verneuil (flame fusion), flux and hydrothermal growth methods; HPHT and CVD diamond synthesis; and the growth features used to separate lab-grown from natural. Price commentary reflects widely reported declines in lab-grown diamond prices during the 2020s and is indicative, not investment advice. Hero photograph: a laboratory-grown brilliant-cut diamond.Independent gem-value research. We don’t sell stones and sellers can’t buy a better verdict.
Informational only — not a formal appraisal or financial advice. For insurance or resale, get a certified appraisal.