A lab-grown diamond is the better choice. It is a real diamond, chemically and structurally identical to a mined diamond, at a price close to moissanite. Moissanite is a different gemstone that only resembles a lab-grown diamond. Once the price gap between a lab-grown diamond and moissanite is this small, there is little reason to choose a stone that isn't a diamond at all.
What Is the Difference Between a Lab-Grown Diamond and Moissanite?
A lab-grown diamond has the same carbon crystal structure as a mined diamond. It is a diamond in every sense, grown in a lab instead of the ground. In 2018 the US Federal Trade Commission removed the word "natural" from its definition of a diamond, so origin no longer decides whether a stone qualifies as a diamond, though sellers must still disclose that a stone is lab-grown. If you want the full picture, see how a lab-grown diamond compares with a mined diamond.
Moissanite is a different material altogether. It is silicon carbide, made in a lab for jewellery. It resembles a lab-grown diamond, but the two are not the same stone, and moissanite is not a diamond by any definition.
Is Moissanite as Hard as a Lab-Grown Diamond?
No. A lab-grown diamond scores 10 on the Mohs hardness scale, the hardest material used in jewellery. Moissanite scores about 9.25. That difference matters over years of daily wear: a lab-grown diamond resists scratching completely, while moissanite, though durable, sits a step below. For how these stones are grown, see what a lab-grown diamond is.
Does Moissanite Show More Fire Than a Lab-Grown Diamond?
Moissanite shows more coloured fire, which comes down to a difference in optical properties rather than quality. The measure is dispersion, or how a stone splits light into colour. Moissanite has a dispersion of 0.104, more than double a lab-grown diamond's 0.044. In larger sizes, this shows up as strong coloured flashes, sometimes called a rainbow or disco effect, which can look artificial rather than refined. A lab-grown diamond's more restrained mix of white and coloured light is the effect most buyers associate with fine jewellery.
Does Moissanite Cost Less Than a Lab-Grown Diamond?
Slightly, yes, though the gap has narrowed to the point where it barely matters. A lab-grown diamond now costs a fraction of what a mined diamond does, so the price advantage moissanite once had is largely gone. Dileti's lab-grown diamond wedding bands start at €740 for the 1 ctw Round Band, a round-prong-set band handmade in Antwerp and delivered across the EU. Lab-grown diamond engagement rings start at €740 and loose lab-grown diamond centre stones start in the low hundreds of euros. Browse lab-grown diamond engagement rings to see prices by size and shape, or lab-grown diamond wedding bands if you're pairing a band with an existing ring.
Can You Tell Moissanite from a Lab-Grown Diamond?
Yes. Moissanite is doubly refractive, so under magnification its facet edges appear doubled. A lab-grown diamond never shows this, because a lab-grown diamond is singly refractive. A jeweller with a loupe or a moissanite tester identifies it in seconds. A basic thermal tester cannot, because moissanite conducts heat much like a lab-grown diamond does. This is also a certification issue: a lab-grown diamond comes with a grading report, and moissanite does not. The centre stone in a Dileti ring, such as the 1 ctw Round Ring, is individually IGI-certified from 1 carat up, with its colour and clarity grade recorded on that report. Smaller accent stones in a setting are not separately certified, so check the certification scope on the product page.
Lab-Grown Diamond vs Moissanite: Which Should You Buy?
| Feature | Lab-Grown Diamond | Moissanite |
|---|---|---|
| What it is | Real diamond, same carbon crystal as a mined diamond | Silicon carbide, a different gemstone |
| Mohs hardness | 10, the hardest jewellery stone | About 9.25 |
| Refractive index | 2.42 | 2.65 to 2.69 |
| Dispersion (fire) | 0.044 | 0.104, more coloured flashes |
| Optical character | Singly refractive | Doubly refractive, facet doubling |
| Certification | Centre stone individually IGI-certified (1ct and above) | Not diamond-graded |
| Price at Dileti | Wedding bands and engagement rings starting from €740 | Not sold at Dileti |
Hardness, refractive index and dispersion figures: GIA.
A lab-grown diamond is the smarter choice for almost every buyer. It is an actual diamond, the hardest stone that exists, and it comes with a certificate recording exactly what you own, all at a price close to moissanite. If you're looking for a single stone on its own, start with lab-grown diamond solitaire rings, designed in Antwerp and shipped free on EU orders over €500.
Frequently Asked Questions
Q1. Is moissanite a real lab-grown diamond?
No. Moissanite is silicon carbide, a different gemstone that looks similar to a lab-grown diamond. A lab-grown diamond is a real diamond, with the same carbon crystal structure as a mined diamond.
Q2. Is moissanite as hard as a lab-grown diamond?
No. A lab-grown diamond scores 10 on the Mohs scale, the hardest known material. Moissanite scores about 9.25, which is durable but not comparable to a lab-grown diamond's resistance to scratching over a lifetime of wear.
Q3. Does moissanite show more fire than a lab-grown diamond?
Moissanite has higher dispersion, 0.104 against a lab-grown diamond's 0.044, so it throws more coloured flashes. In larger sizes, this can look more artificial than refined. A lab-grown diamond's steadier mix of light is what most buyers associate with fine jewellery.
Q4. Does moissanite cost less than a lab-grown diamond?
Slightly, though the gap has narrowed so much it rarely matters. A lab-grown diamond now costs a fraction of a mined diamond's price, so an actual diamond is realistically within reach. Dileti's lab-grown diamond wedding bands and engagement rings start at €740.
Q5. Can you tell moissanite from a lab-grown diamond?
Yes. Moissanite is doubly refractive, so under magnification its facet edges appear doubled, and dedicated testers pick this up. A basic thermal tester cannot, because moissanite conducts heat much like a lab-grown diamond does.
Q6. Why choose a lab-grown diamond over moissanite?
A lab-grown diamond is an actual diamond, the hardest stone available, and comes with an IGI certificate for centre stones of 1 carat or more. Moissanite is not a diamond and is not certified as one, so for the same price range, a lab-grown diamond gives you more of what a diamond is meant to be.
Ready to Choose Your Lab-Grown Diamond Ring?
Browse Dileti's lab-grown diamond engagement rings, with IGI-certified centre stones from 1 carat, engagement rings and wedding bands starting from €740. Every piece is designed in Antwerp and delivered across the EU, with free shipping on orders over €500 (see shipping and delivery for full details).
