The Best Lab Grown Diamond Jewellers in Australia, Compared

I sell lab grown diamond engagement rings, and one of the six businesses compared below is mine. You should read the rest of this page knowing that. A comparison written by a competitor is worth something only if it is checkable, so everything in the table came from each company's own live website, read in August 2026, and where a company does not publish a fact I have written "not published" rather than guessing at it. If you find a line you think is wrong, it is because their site changed or I read it badly, and I would rather hear about it than have it sit here.

I have also given four of the five other businesses a category where they beat us outright. That is not false modesty. We are a two person operation in Southbank, Melbourne, and there are several things a national chain does better than we do.

How I chose the dimensions

Most "best jeweller" lists rank on vibe. Vibe is unfalsifiable, so I have used five things that are either true or not true and that you can verify yourself in about ten minutes:

Physical locations. Whether you can put the stone under a light with your own eyes before you commit, and in which cities.

Loose stones. Whether the business will sell you the stone on its own, so you can set it elsewhere or later. This matters more than people expect. It is the difference between buying a product and buying a component.

Certification laboratory. Which lab grades the stones, published on their own site. A retailer who will not name the lab on their website is not necessarily hiding anything, but they are making you ask.

Custom work. Whether they will make something that does not exist in the catalogue.

A published starting price. Not the number itself, which moves weekly, but whether they put one in front of you before you fill in a form.

I have deliberately not compared warranty terms, turnaround or price levels. Those change, they are often buried in terms and conditions, and quoting a competitor's warranty from memory is how misinformation starts. Ask each of them directly and get the answer in writing.

The comparison table

	Physical locations	Sells loose stones	Certification lab named on site	Custom design	Publishes a starting price
Cullen Jewellery	Melbourne, Sydney, Brisbane, Adelaide, Perth and Auckland, plus five US cities. By appointment	Not published	Yes. States most lab grown diamonds are IGI certified	Yes	Not published on the home page
Novita Diamonds	Sydney CBD, Parramatta, Melbourne, Brisbane, Adelaide, Perth, plus overseas locations	Yes. States over 2,400 lab grown diamonds available in Australia for in person viewing	Not published on the pages read	Yes. States they can custom make any design	Yes, for a loose stone, on the home page
Moi Moi Fine Jewellery	Sydney flagship in the QVB and Melbourne flagship on Collins Street, open 7 days. Perth also referenced	Yes. Loose moissanite and loose lab grown diamonds, including colour	Not published on the pages read	Yes. Describes itself as expert in custom design	Yes, per design, on product listings
Temple and Grace	Sydney, Melbourne, Brisbane, Perth and Adelaide	Yes. Full loose diamond section, browsable by cut	Not published on the pages read	Yes	Not published on the home page
Michael Hill	Retail stores across Australia, New Zealand and Canada. Store count not published on the about page	Not published	Not published on the pages read	Bespoke service and a ring builder are listed	Not published on the home page
Guthrie Jewellery (us)	One studio, Southbank, Melbourne, by appointment	No. We sell finished rings only	Yes. IGI for lab grown diamond, GRC for moissanite	Yes	Yes. Lab grown from AU$1,350, moissanite from AU$800

Two entries in that table are worth pulling out because they are unusual in this market. Cullen states plainly on its FAQ that it does not sell mined diamonds. Michael Hill sells both mined and lab grown, and its engagement range includes natural diamond collections alongside its lab range. Temple and Grace carries mined diamonds, lab grown diamonds and moissanite together. That single distinction shapes more of your buying experience than any of the others, and I will come back to it.

Best for seeing a lot of stones in person: Novita Diamonds

Novita publishes six Australian locations and states that over 2,400 lab grown diamonds are available in Australia for in person viewing. If you are the kind of buyer who does not believe a stone until it is on a tray in front of you, and you want to compare a dozen of them side by side in one sitting, that inventory depth is a real advantage and we do not have anything like it. We hold stones for specific commissions. We are not a diamond floor.

They also sell loose stones, which means you can buy the diamond from them and take it to a setter you already trust. That is a genuinely good option for anyone who has a family jeweller and only needs the stone.

Best for walking in without an appointment: Moi Moi Fine Jewellery

Moi Moi states its Sydney and Melbourne flagships are open seven days, and it has been selling in this category since 2004, which is well before most of the Australian lab grown market existed. Long trading history in a category that is full of two year old brands is worth something.

If your situation is that you are in the city on a Saturday, you have ninety minutes, and you want to try things on without booking anything, we lose that comparison outright. Our studio is appointment only and always will be, because there is one bench and I am usually at it.

Best for after sales access outside a capital city: Michael Hill

Michael Hill has operated since 1979 and trades across Australia, New Zealand and Canada. If you live in a regional centre, the practical question five years after the purchase is not who has the best marketing, it is who has a counter you can walk into when a claw lifts. A national retail network answers that question in a way a single Melbourne studio does not.

We ship insured and carbon offset Australia wide and we handle repairs by post, which works. It is not the same as a shopfront twenty minutes away, and I am not going to pretend it is.

Best for comparing mined and lab grown in the same visit: Temple and Grace

Temple and Grace lists boutiques in five capital cities and carries mined diamonds, lab grown diamonds and moissanite, with a full loose diamond section you can browse by cut. If you have not decided between mined and lab grown, and you want to hold both under the same lighting on the same afternoon, a retailer who stocks both is the only way to do that honestly. We cannot help you with that comparison at all, because we hold one side of it.

There is a trade off, which I will state as neutrally as I can. A retailer carrying both has a commercial interest in how you choose between them, and it will not always point the same way. That is not an accusation about any particular business. It is a structural fact about carrying two products at very different margins, and it applies to every multi category jeweller including the ones with excellent reputations. Ask directly why they are recommending what they are recommending, and see whether the answer is about the stone or about the stock.

Best for a physical presence in more than one country: Cullen Jewellery

Cullen lists locations in Melbourne, Sydney, Brisbane, Adelaide, Perth and Auckland, and has opened in five US cities. It names IGI as the grading lab for most of its lab grown diamonds on its own FAQ, which more retailers should do. It also states clearly that it does not sell mined diamonds.

If you are moving overseas, or you are buying from one country for someone in another, that footprint solves a problem that a Melbourne bench cannot.

Where we fit, and where we do not

We are Guthrie Jewellery. I make the rings in a Southbank studio in Melbourne, by appointment. Here is the honest shape of that.

What we are genuinely better at. The person who designs your ring is the person who makes it and the person who repairs it. There is no handoff, no offshore casting house, no account manager relaying a question to a workshop. When you ask how thick the shank is at the base, or whether the claws will clear a wedding band on your specific finger, you get an answer from the bench rather than from a script. Every lab grown diamond we set is IGI certified and laser inscribed on the girdle with its report number, so you can match the stone to the paper yourself. Craftsmanship and the optical properties of the stone carry a lifetime warranty, and the first resize is free within three months of purchase.

We also do not carry mined diamonds, which removes an entire class of sales pressure from the conversation. There is no more profitable stone in the cabinet for me to steer you toward.

What we are worse at. We have one location. If you are in Perth or Brisbane or Toowoomba, you are buying from photographs, a video call and a free ring sizer, and for some people that is not enough, which is fair. We do not sell loose stones, so if you want to buy a diamond and set it somewhere else, we are the wrong shop. We hold nothing like the in person diamond inventory the larger businesses do. We are small, which means we are slower to answer at 9pm on a Sunday than a company with a support team. And because we do not carry mined diamonds, we cannot give you a genuinely balanced in person comparison between mined and lab grown. If that comparison is the thing you need, go to someone who stocks both.

If you want to see the range before deciding whether any of that suits you, the lab grown diamond engagement rings collection is the place to start, and you can book an appointment in Melbourne or by video call.

What none of this tells you

The table above compares businesses. It does not compare rings, and after five years of wear the ring is what you have.

Three questions do more work than any comparison table:

How thick is the band at the base, in millimetres? Under about 1.8mm on a daily wear ring, on hands that do physical work, you are looking at a shank that thins and eventually splits. This number is knowable and most retailers will tell you if you ask.

Who physically repairs it, and where? If the answer routes through an overseas workshop, add the shipping time to every future repair estimate.

Is the cut grade excellent, and can I see the certificate before I pay? Cut is the only line on a grading report that changes how the stone reads across a room. Colour and clarity are negotiable. Cut is not. If you want to know how to read the report properly, what an IGI certificate actually tells you covers checking the report number against IGI's own database rather than taking anyone's word for it.

How I would actually decide

If you want maximum stone choice in person, go to the businesses with the largest floors and the loose stone inventory. If you want a shopfront you can walk into for the next twenty years anywhere in the country, weight that heavily and accept the trade offs that come with scale. If you have not settled the mined versus lab grown question, go somewhere that stocks both and interrogate the recommendation you get. If you want the maker to be the person you talk to, and you can get to Melbourne or are comfortable buying at a distance, that is us.

If you are still deciding between stone types before you decide between jewellers, lab grown versus mined diamonds is the more useful page to read first, and moissanite versus lab grown diamond covers the other fork.

FAQ

Is this comparison independent?

No. It is written by one of the six businesses in it. Every factual claim about the other five was taken from their own live websites in August 2026, and anything they do not publish is marked "not published" rather than filled in. Verify anything that matters to you directly with the business.

Why are there no prices for the other jewellers?

Because quoting a competitor's price is the fastest way to publish something false. Ring prices move with metal rates, stone supply and promotions, and a figure that is right today is wrong in a month. The table records whether each business publishes a starting price at all, which is the durable fact.

Does buying a loose stone save money?

Sometimes, and it shifts risk onto you. You take on matching the stone to a setting, the setting quality, and any dispute about which party is responsible if something goes wrong during setting. If you already have a jeweller you trust to do the setting, it is a good route. If you do not, buying the finished ring from one accountable party is simpler.

Do lab grown diamonds from different Australian retailers differ in quality?

The stones come from a relatively small number of growers, so two IGI certified stones of the same carat, colour, clarity and cut grade from two retailers are close to interchangeable. The difference between retailers sits almost entirely in the setting, the finishing and what happens when something needs repair.

Which lab grading report should I look for?

IGI grades the majority of lab grown diamonds sold in Australia, and GIA also grades them. Either is fine. What matters is that the report number is laser inscribed on the girdle so the paper can be matched to the actual stone, and that you check the number on the laboratory's own database rather than a retailer's screenshot.