Moissanite vs Lab-Grown Diamond: Which Diamond Alternative Is Right for You?

Rainbow moissanite statement ring, 2 carat, in sterling silver

Lab-created moissanite in sterling silver — the affordable, high-fire alternative

If you've decided against a mined diamond, you've almost certainly come across the two alternatives everyone talks about: moissanite and lab-grown diamond. They're often mentioned in the same breath, as though they're interchangeable. They aren't. One is an actual diamond made in a laboratory; the other is a completely different gemstone that happens to look similar. Understanding that distinction is the key to choosing well — and to not overpaying.

This is an honest comparison. We sell moissanite, not lab-grown diamonds, so we'll be upfront about where each one wins and where moissanite has a genuine edge, rather than pretending one is perfect. Both are excellent, ethical, affordable choices compared with a mined diamond. The right pick simply depends on what matters most to you: the lowest price and the most sparkle, or owning something that is, technically and chemically, a real diamond. Here's everything you need to weigh it up.

The short version

A lab-grown diamond is a real diamond — chemically identical to a mined one — just made above ground; it has the classic diamond look and costs less than mined, but more than moissanite. Moissanite is a different stone (silicon carbide) that is nearly as hard, throws even more sparkle, and costs a fraction of the price. Choose a lab diamond if owning “a real diamond” matters to you; choose moissanite for maximum brilliance at the lowest cost.

What each one actually is

A lab-grown diamond (also called lab-created or cultivated) is carbon crystallised into diamond in a reactor rather than in the earth. It is a genuine diamond in every physical and chemical sense — identical to mined, and graded on the same 4Cs. The only difference from a natural diamond is origin, as our lab-grown vs natural diamonds guide explains.

Moissanite is not a diamond and doesn't pretend to be. It is silicon carbide — first discovered in a meteorite — and today grown in laboratories as its own distinct gemstone with its own optical character. It looks similar to a diamond to the naked eye but has a livelier, more colourful sparkle. It's the stone in every piece we make.

How they compare, honestly

Factor Lab-grown diamond Moissanite
What it is A real diamond (carbon) A different stone (silicon carbide)
Hardness (Mohs) 10 — the hardest ~9.25 — extremely hard-wearing
Sparkle Classic diamond brilliance More fire — extra rainbow flashes
Price for the same size £££ — less than mined, more than moissanite £ — a fraction of a lab diamond
Diamond tester Reads as diamond (it is one) Reads as moissanite on a dual tester
Resale value Low and falling Very little — buy to wear
Origin Lab-made, no mining Lab-made, no mining

Durability: both are built for everyday wear

A lab diamond sits at the very top of the Mohs hardness scale at 10; moissanite is close behind at around 9.25 — second only to diamond among stones you'll realistically wear, and far tougher than sapphire, CZ or anything else. In real life, both resist scratching and daily knocks extremely well and will stay brilliant for years. For an everyday piece, the practical difference in hardness is negligible; for a true multi-generation heirloom, the diamond's edge counts for a little more. Our guide to the Mohs scale puts the numbers in context.

Sparkle: the clearest visible difference

This is where the two genuinely diverge. A lab diamond has the restrained, white brilliance people associate with diamonds. Moissanite has more than double the fire — the flashes of rainbow colour — so it's noticeably livelier, especially in larger sizes and bright light. Whether that's a plus or a minus is pure preference: some people adore the extra sparkle and lean into it, as with our Rainbow Moissanite Studs; others prefer the classic, icy diamond look and choose a lab diamond for that reason. Neither is “better” — they're different aesthetics.

Price: the biggest practical gap

Both are far cheaper than a mined diamond, but they are not priced the same. A lab-grown diamond typically costs several times more than a moissanite of the same size, because it is, after all, an actual diamond. Moissanite is the most affordable of the three by a wide margin, which is what lets you have real presence — a 2-carat-equivalent showpiece like our Rainbow Moissanite Statement Ring at £221.99 — without a four-figure outlay. If budget or getting the biggest, most brilliant look for your money is the priority, moissanite wins comfortably.

Testing, certification and “will people know?”

A lab diamond passes a standard diamond tester because it is diamond; moissanite is identified by a dual moissanite/diamond tester (older diamond-only testers can be fooled, as we explain in how to tell if a diamond is real). Lab diamonds usually come with a grading certificate (IGI or GIA); moissanite is graded too but rarely certified in the same way. To the naked eye, most people simply see a beautiful, sparkling white stone either way — and there's no reason to feel you must hide a sensible choice about your own money.

Resale and value — buy either to wear, not to trade

Here's the honest part: neither holds its value. Moissanite has very little resale value because it's affordable and easy to produce. Lab-grown diamond prices, meanwhile, have fallen sharply as production has scaled, so lab diamonds also make poor investments and resell for far less than they cost. If you're buying to enjoy and wear — which is how almost all jewellery is actually used — this is a non-issue for both. If you specifically want resale or heirloom-asset value, only a mined diamond offers an established second-hand market, and even then usually at a loss.

Ethics and sustainability

Both share the big ethical advantage over mined stones: no mining, known origin, and no murky supply chain. Neither is completely impact-free — growing stones uses energy — but both sidestep the land disruption and traceability problems of mining, which for many buyers is the deciding factor. On this measure, it's essentially a tie.

So which should you choose?

Choose a lab-grown diamond if: owning a genuine diamond matters to you emotionally or traditionally; you want the classic, restrained diamond look; or you (or a partner) specifically want a certified diamond for an engagement ring and the mid-range budget works.

Choose moissanite if: you want the most sparkle and the biggest look for the lowest price; you love — or don't mind — the extra fire; you're buying jewellery to wear and enjoy rather than as an asset; or you simply want beautiful, hard-wearing brilliance without a large outlay. For most everyday pieces — studs, pendants, statement rings — moissanite is the sensible, joyful choice, which is exactly why it's what we make.

The bottom line

Moissanite and lab-grown diamond are both excellent, ethical, mining-free alternatives — but they're different things. A lab diamond is a real diamond at a mid-range price with the classic look; moissanite is a distinct stone that's nearly as hard, sparkles even more, and costs a fraction as much. Neither is an investment, so buy whichever you'll love wearing. If that's maximum brilliance for the most sensible price, moissanite is hard to beat.

See how it looks set in solid sterling silver across our Moissanite Collection — from everyday studs to statement rings.

Related reading:
Moissanite vs Diamond: An Honest Comparison
Lab-Grown Diamonds vs Natural Diamonds: What's Actually Different?
Moissanite vs Cubic Zirconia: Choosing Your Diamond Alternative