Are Lab-Grown Gemstones Real? Natural, Synthetic and Simulant Explained
Is a lab-grown ruby a real ruby?
Ask three sellers and you'll get three different answers. One says yes, it's the same thing. Another says no, it's fake. A third says "it depends," and then changes the subject.
They're all partly right, because "real" means two different things. This guide sorts out the vocabulary the gem trade uses, what each word means, and how it applies not just to cut gemstones but to the crystals and specimens people buy too.
The short answer: a lab-grown gemstone is made of the same material as its natural version, so a lab ruby is genuine ruby. But it's not natural, and it should always be sold as lab-grown. A simulant, like glass or cubic zirconia, is a different material that only looks like the stone.
Four words that get mixed up
Almost every confusion in this topic comes from these four terms being swapped around.
| Term | What it is | Example | Same material as the named gem? |
|---|---|---|---|
| Natural | Formed in the earth | A mined sapphire | Yes |
| Treated (enhanced) | A natural stone changed after mining | Heated ruby, dyed agate | Yes, but altered |
| Synthetic (lab-grown, lab-created) | Made by people with the same composition and structure | A lab-grown ruby | Yes |
| Simulant (imitation) | A different material that looks similar | Glass, cubic zirconia | No |
"Synthetic," "lab-grown" and "lab-created" mean the same thing. "Synthetic" is the older gemological term. Many sellers now prefer "lab-grown" because "synthetic" can sound like "fake" to shoppers.
Treated stones deserve their own mention, because people often lump them in with lab-grown ones. A heated amethyst sold as citrine is a natural stone that was changed. It isn't lab-grown, and it isn't a simulant either.
So are lab-grown gemstones real?
It depends which "real" you mean.
Real as in the same material: yes
A lab-grown ruby is corundum with chromium in it, just like a mined ruby. It has the same chemistry, the same crystal structure and the same hardness. Gemologists treat it as ruby. GIA says the same about lab-grown diamonds: they have the same chemical, physical and optical properties as natural ones, which simulants don't.
Real as in natural: no
It wasn't formed in the earth over millions of years, and that matters to a lot of buyers. Natural stones are rarer, and rarity is a big part of their price. Lab-grown stones are made on demand, so they cost far less than natural stones of the same quality.
This is also why the rules about labels are strict. In the US, the FTC's Jewelry Guides expect a lab-origin word such as "laboratory-grown," "laboratory-created" or "synthetic" to come right before the stone's name and to be just as prominent. They also warn against calling a lab product "real," "genuine" or "natural." In 2018 the FTC dropped the word "natural" from its definition of a diamond, so a lab-grown diamond is a diamond, but it still has to be labeled as lab-grown.
Why the price gap exists
Think of it like pearls and ice. You can freeze water in a factory or find a glacier, and both are real ice. Only one is rare, and you'd expect a different price tag.
Lab-grown stones are abundant, so they're cheap compared with natural ones. A seller who quotes you a natural price for a lab-grown stone is the problem, not the stone itself.
How lab-grown gems are made
You don't need to memorize this, but knowing the methods explains why the stones look the way they do.
| Method | How it works | Typical stones | What a gemologist may see |
|---|---|---|---|
| Flame fusion (Verneuil) | Powder is melted in a flame and grows into a rod called a boule | Ruby, sapphire, spinel | Curved growth lines, gas bubbles |
| Flux growth | Crystals grow slowly from a molten salt solvent | Ruby, sapphire, emerald | Wispy "fingerprint" veils |
| Hydrothermal | Crystals grow in hot, pressurized water | Quartz (amethyst, citrine), emerald | Chevron-shaped growth zoning, sometimes a seed plate |
| HPHT and CVD | High pressure and heat, or chemical vapor deposition | Diamond | Needs lab instruments to spot |
The key idea is that all of these copy what nature does, only faster and in a controlled setting.
Simulants can be natural stones too
Here's a twist that surprises people. A simulant isn't always man-made. GIA points out that natural stones, such as colorless quartz, topaz, sapphire, beryl and especially zircon, have been used as diamond simulants for centuries.
So a stone can be 100 percent natural and still be sold dishonestly, if it's passed off as something else. Our guide to zircon and cubic zirconia is a good example of how two different materials with similar names get confused. If you want to know whether you're looking at a natural stone, the question isn't just "is it lab-made?" It's "is it the stone the seller says it is?"
The crystal-shop version: man-made "stones"
The terms above work for crystals and specimens too, and this is where many buyers get caught. Several popular "crystals" aren't minerals at all.
| Name | What it really is | Fine if the seller says... |
|---|---|---|
| Opalite | Opalescent glass, sometimes sold as "sea opal." It can contain air bubbles | "Man-made glass" |
| Goldstone | Glass with tiny flecks of copper. Blue and green versions use cobalt and chromium | "Manufactured glass" |
| Cherry quartz | Usually glass or dyed material. There's no natural red quartz that looks like this | "Dyed glass" |
| Lab-grown quartz clusters | Quartz grown in a lab, often in very bright colors | "Lab-grown quartz" |
| Bismuth crystals | A metal melted and cooled into stepped, rainbow shapes | "Man-made bismuth" |
| Aura quartz | Real quartz with a thin metal coating (a treatment, not man-made) | "Natural quartz, coated" |
None of these is wrong to sell. The problem comes up when the label is missing, or when a buyer thinks they're getting a natural mineral. A mineral specimen is a piece of the earth, with matrix, imperfections and no identical twin. Man-made pieces can be made in any shape, over and over.
Can you tell at home?
For lab-grown stones, mostly no. GIA notes that the difference can be impossible to see by eye, and separating natural from lab-grown diamonds can take advanced instruments. Flame-fusion, flux and hydrothermal stones can show clues, but you'd need a loupe, practice and a bit of luck.
Glass is easier. A few clues are worth checking.
Clues that help
- Round bubbles. Glass often has them. Natural stones can have inclusions, but those are usually angular, wispy or feathery, not round.
- Unnaturally uniform color with no zoning or variation.
- Mold seams or a slightly soft, rounded look on the edges.
- Color pooled in cracks. That points to dye.
- Curved growth lines under a loupe, which suggest flame-fusion growth.
Clues that mislead
- Temperature. Glass warming up faster can be a hint, but it's easy to misread.
- "It has inclusions, so it's natural." Lab-grown stones can have inclusions too.
- "It's too clean, so it's fake." Some natural stones really are clean.
- Price alone. A cheap price is a flag, but not proof.
When to get a lab report
For a stone worth real money, or any piece you may resell, a report from a gemological lab settles the question. Our guide to GIA, GRS and Gübelin reports explains how they differ. For general red flags, see our beginner's guide to identifying real versus fake gemstones.
What to ask any seller
These questions work for any seller, anywhere.
- Is it natural, treated, lab-grown or a simulant? Ask for one word.
- Has it been heated, dyed, coated or irradiated? Treatment should be disclosed.
- Where is it from? Dealers who know their supply can answer.
- Can I get that in writing on the invoice? A clear description in writing is worth more than a verbal promise.
- What's the return policy if it isn't what you described?
Our guide to buying loose gemstones without getting scammed has a longer checklist.
So which one should you buy?
There's nothing wrong with lab-grown stones, as long as they're labeled honestly. If you want a bright, flawless stone at a lower price, a lab-grown one can be a smart choice. If you care about rarity, geology and owning a piece that formed in the earth, natural is the point. Both are honest choices.
For collectors of mineral specimens, natural origin usually is the whole point. A specimen's matrix, crystal shape and flaws tell the story of where it grew. To see how raw pieces and cut stones differ, read our guide to mineral specimens vs gemstones, or start with what a mineral specimen is.
Browse raw pieces in our specimens and crystals collection, or cut stones in loose gemstones.
Frequently asked questions
Are lab-grown gemstones real?
They're real in the sense that they have the same chemistry and structure as natural stones. A lab-grown ruby is genuine ruby. But they aren't natural, and they should be sold as lab-grown.
Is synthetic the same as lab-grown?
Yes. "Synthetic," "lab-grown" and "lab-created" all mean a stone made by people with the same composition and structure as the natural one. "Synthetic" is the older gemological term.
What's the difference between synthetic and simulant?
A synthetic is made of the same material as the natural stone. A simulant is a different material that only looks like it, such as glass or cubic zirconia.
Can a natural stone be a simulant?
Yes. Colorless quartz, topaz and zircon have all been used to imitate diamond. A natural stone becomes a simulant when it's passed off as something else.
Is opalite a real crystal?
No. Opalite is man-made opalescent glass, not a natural mineral. It's fine to buy if it's labeled honestly.
Can you tell a lab-grown stone from a natural one at home?
Usually not. Glass is easier to spot because of round bubbles and uniform color, but lab-grown stones often need a loupe or lab instruments. For valuable stones, get a lab report.