Moissanite and lab-grown diamonds are often presented as interchangeable alternatives to mined diamonds. They are not. One is a diamond; the other is a different material with its own look, strengths and trade-offs.
This guide sets out the differences plainly, so you can decide which suits a ring you will wear every day. Where the honest answer favours moissanite, we say so.
Is moissanite the same as a lab-grown diamond?
No. Moissanite is silicon carbide, a crystal of silicon and carbon, while a lab-grown diamond is pure crystallised carbon. A lab-grown diamond is chemically, physically and optically identical to a mined diamond; moissanite is a separate gemstone that resembles diamond at a glance but behaves differently under close inspection.
Natural moissanite is so rare that virtually every moissanite sold in jewellery is grown in a laboratory; the name refers to the material, not to how it was made. A gemologist separating a lab-grown diamond from a mined one needs specialised equipment, whereas separating moissanite from diamond is far simpler. Read more about how the stones are grown and graded on our lab-grown diamonds page.
How does the sparkle differ between moissanite and a lab-grown diamond?
Moissanite has noticeably higher dispersion than diamond, so it throws more coloured flashes, often described as rainbow fire. A diamond's return of light is whiter and more restrained, with the balance of white flashes and dark contrast associated with a classic engagement ring.
Diamond's dispersion is around 0.044; moissanite's is roughly 0.104, more than double. Moissanite is also doubly refractive, which in larger stones can produce a subtle doubling of the back facets, something singly refractive diamond never shows.
Neither look is objectively better. Some wearers love the vivid, almost prismatic quality of moissanite; others find it slightly artificial and prefer the quieter brilliance of diamond.
Which is harder and more durable for daily wear?
Diamond is the hardest known natural material at 10 on the Mohs scale; moissanite sits at 9.25. Both are hard enough for a ring worn every day, and both are harder than sapphire, the next hardest gemstone commonly used in rings. The practical difference is small, though diamond resists fine scratches for longer over decades of wear.
Hardness measures scratch resistance, not resistance to chipping. Any gemstone, diamond included, can chip if it takes a sharp knock on a thin edge, which is why the setting matters as much as the stone. VAALBERG offers free resizing and lifetime care on every ring, whatever stone it holds.
Does moissanite show a colour tint?
It can. Many moissanites, particularly older or lower grades, show a faint yellow, green or grey cast that becomes more apparent in daylight and in larger sizes. Newer production is closer to colourless, but check in person, because a tint is easy to miss under warm shop lighting.
Lab-grown diamonds are graded on the standard D-to-Z colour scale, so the amount of tint is documented rather than guessed. Our Classic tier uses G–H colour stones; Reserve uses F; Signature uses D–E, the top of the scale. Moissanite is sometimes described with diamond-style colour letters, but those are the seller's own descriptions, not grades from an independent laboratory.
Can moissanite be certified like a lab-grown diamond?
Not in the same way. IGI and GIA issue diamond grading reports assessing cut, colour, clarity and carat weight against established standards; moissanite is not a diamond and does not receive that report. Moissanite typically comes with a manufacturer's warranty card or a seller's grading, which is useful but not independent.
A grading report matters because it makes the purchase verifiable. Lab-grown diamonds graded by IGI or GIA are laser-inscribed on the girdle with their report number, so the stone can be identified years later by any jeweller. Details of what the reports contain are published by IGI and GIA.
Every diamond VAALBERG sells carries an IGI or GIA report, and every stone is inspected in Sweden against that report and photographed before it ships. Both are shown on the product page, so what you see is the stone you receive.
Which costs less, moissanite or a lab-grown diamond?
Moissanite is generally the cheaper of the two, size for size. Lab-grown diamond prices have fallen considerably, so the gap is narrower than it once was, but moissanite of equivalent size will usually still cost less than a certified lab-grown diamond.
Moissanite is less dense than diamond, so it is usually sold by millimetre size or "diamond equivalent weight" rather than actual carat weight. Compare stones by millimetre footprint, and use the "See it true to size" visualiser on our product pages to check real dimensions against a coin or a fingertip.
VAALBERG prices are all-inclusive: diamond, setting, certificate, insured worldwide shipping and VAT, with nothing added at checkout and no traditional industry markup. Loose stones start from about 1,500 SEK, and you can compare sizes and grades in the diamond search.
What about resale value?
Low, for both. Neither moissanite nor a lab-grown diamond should be bought as an investment, and neither is likely to be resold for anything close to the purchase price. Buy either stone for what it is and how it looks, not for what it might be worth later.
Lab-grown production is scalable and moissanite even more so, which keeps second-hand values low; the value of an engagement ring lies in wearing it.
How do moissanite and lab-grown diamonds compare side by side?
The table below summarises the differences that matter most for an engagement ring; it describes typical, well-made stones of each type.
| Property | Lab-grown diamond | Moissanite |
|---|---|---|
| Composition | Pure carbon; identical to mined diamond | Silicon carbide; a different gemstone |
| Hardness (Mohs) | 10 | 9.25 |
| Sparkle character | Whiter, balanced brilliance; dispersion about 0.044 | Strong rainbow fire; dispersion about 0.104 |
| Refraction | Singly refractive | Doubly refractive; possible facet doubling |
| Colour | Graded D to Z by an independent laboratory | May show warm or greyish tint in daylight; seller-described |
| Certification | IGI or GIA diamond grading report | No diamond grading report; manufacturer warranty at most |
| Price | Higher, though far below mined diamond | Generally lower for the same size |
| Resale value | Low | Low |
| Daily wear | Excellent | Very good |
Who is moissanite right for, and who should choose a lab-grown diamond?
Moissanite suits buyers who want the largest possible stone on a tight budget, enjoy vivid rainbow fire and are unconcerned about certification. A lab-grown diamond suits those who want an actual diamond, a whiter and more classic sparkle, an independent grading report and greater hardness.
Choose moissanite if:
- budget is the deciding factor and size matters more than material;
- you have seen its fire in daylight and prefer it;
- you are happy to rely on a seller's description rather than a laboratory report.
Choose a lab-grown diamond if:
- it matters to you, or to the person receiving the ring, that the stone is a diamond;
- you prefer restrained white brilliance to coloured flashes;
- you want a certified, laser-inscribed stone that any jeweller can identify.
Many people who compare the two in person choose diamond once the price gap turns out to be smaller than expected. A certified stone from our 1 carat lab-grown diamonds is within reach of budgets that once pointed towards moissanite.
How should you decide between moissanite and a lab-grown diamond?
Decide on three things in order: material, look and budget. If it matters that the ring holds a diamond, the choice is made; if not, look at both stones in daylight and trust your own eye on the sparkle; then fit the size to the budget rather than the other way round.
Whichever you choose, insist on seeing the specific stone rather than a stock photograph. If you would like to talk it through, a named VAALBERG expert is reachable by phone, chat or email, and will say honestly if a smaller, better-cut stone would serve you better.
You can build a ring in the ring configurator, or browse finished designs among our engagement rings. Every purchase comes with free insured delivery and 30-day returns with a full refund, so the decision does not have to be final.
Frequently asked questions
Can you tell moissanite from a lab-grown diamond by eye?
Often, yes, once you know what to look for. Moissanite's stronger rainbow fire, its faint tint in daylight and, in larger stones, a slight doubling of the back facets are all visible to a trained eye. A jeweller can confirm the difference in seconds.
Does moissanite pass a diamond tester?
Basic thermal testers often read moissanite as diamond, because the two conduct heat similarly. Jewellers therefore use electrical-conductivity testers or optical checks to separate them, one reason an independent laboratory report matters when buying a diamond.
Is a moissanite engagement ring durable enough for daily wear?
Yes. At 9.25 on the Mohs scale moissanite is harder than every gemstone apart from diamond, and it does not lose its polish or become cloudy with normal wear. A sensible setting and occasional prong checks keep it secure.
Will a lab-grown diamond hold its value better than moissanite?
Not meaningfully. Both have low resale value, and neither should be bought with future value in mind. What a lab-grown diamond does hold is its identity: a certified, laser-inscribed diamond remains verifiable for life, which moissanite cannot offer.
Is a lab-grown diamond a real diamond?
Yes. It has the same chemical composition, crystal structure and optical properties as a mined diamond, and it is graded on the same scale by the same laboratories. The only difference is origin, which is why IGI and GIA reports state that the stone is laboratory-grown.
