30 Carat Lab-Grown Diamonds: What Exists and How to Source One

The short version: Yes, 30 ct lab-grown diamonds exist, but at that weight they are rare, mostly fancy color, and bought by specification rather than from a shelf. Liora Diamond's live listing showed five stones of 25 ct and above, three of them over 30 ct: a 30.16 ct Fancy Intense Pink Pear, a 30.09 ct Fancy Light Brownish Pink Heart, and a 30.08 ct Fancy Intense Pink Cushion, all CVD-grown with IGI reports. A white 30 ct stone was not in that listing; it would be sourced or grown to order, with a date confirmed in writing before you commit. Liora Diamond supplies businesses only, with Surat as its base.

How Big Have Lab-Grown Diamonds Become?

Size has moved quickly. In May 2023, GIA reported examining a 34.59 ct emerald-cut CVD laboratory-grown diamond, G color and VS2, measuring 24.94 × 13.95 × 9.39 mm. GIA noted it was more than double the 16.41 ct CVD stone it had reported a year earlier. National Jeweler's coverage said the stone was grown by Ethereal Green Diamond of Mumbai and that GIA's researchers confirmed post-growth HPHT annealing was used to bring the color up to G. That detail matters for buyers: growth and finishing are often separate steps, and the report is where this is recorded.

Larger stones have since been shown. Jeweller Magazine reported in June 2024 that a 75.33 ct square-emerald-cut lab-created diamond, cut from a 190 ct rough and graded by IGI, was displayed at the JCK show in Las Vegas. We found that figure in one trade report and have not seen the IGI report ourselves, so treat it as reported rather than independently verified. These are showpieces. They tell you what growers can achieve, not what you can order at wholesale next month, and none of them is a statement about Liora's own capacity.

What is Available at 30 CT Today at Liora Diamond?

Here is what Liora's 25 ct and above listing showed on:

Three observations. First, the whole tier is pink-family, which is consistent with what we found in the large pink guide. Second, the shapes are pear, heart, and cushion, so a buyer who needs a round brilliant or an emerald cut at this weight should also be available at Liora Diamonds. Third, for complete pricing details, request via WhatsApp. You can open the live view yourself at 25 ct and above or browse by shape: pear, oval, and radiant are the shape filters in the site footer.

The tier below it is easier to buy. Our 20 carat guide, 10 carat guide, and 5 carat guide cover the stones that more often make it to a finished piece.

Why Are Most 30 Carat+ Stones Fancy Color?

Stock is not a market study, so we only claim what the listing shows: at 25 ct and above, every stone is a fancy pink. There are three plausible reasons, and we label them as interpretation, not fact.

1. Fancy color hides some of the inclusions that a large white stone would show.
2. Color is part of the value of a statement stone, so a buyer will accept a stone that a white-only buyer would reject.
3. Large stones are expensive to grow and cut, which favours output that sells readily.

Liora's fancy-color diamond page says lab-grown fancy colors are usually created or intensified after growth, that the grading report records this, and that the invoice states it. Our fancy-color supplier guide and the white vs fancy color sourcing guide explain the trade-offs. Browse current pink stones if pink is your range.

Note the third stone above: Fancy Light Brownish Pink is a lighter, modified color, and at SI1 it will read differently from the two Fancy Intense stones. Grade ranges, not single grades, are how buyers shortlist at this weight.

What Does 30 CT Look Like in Millimetres?

Diamond carat represents the weight, not its actual size. The shape of the diamond changes the footprint. What we can do is use measured stones. Liora's a 25.07 ct heart (ref LDA9666B) at 18.28 × 20.35 × 9.01 mm. Scaling those proportions to 30 ct by cube-root weight gives roughly 19.4 × 21.6 × 9.6 mm. That is an illustration of order of magnitude, not a measurement: real stones differ in depth and outline. For comparison, GIA's 34.59 ct emerald cut was 24.94 × 13.95 × 9.39 mm, which shows how much longer and narrower a step cut can be at similar weight. If a setting has a fixed seat, send the seat dimensions with the request.

How Do You Source a White 30 CT+ Stone in Wholesale?

Liora's Big Diamonds page states that every size is available in white and fancy color, that larger or exact-spec stones are grown to order, and that a date is given before you commit. Its size table lists 10–20 ct as selected stock or grown to order and 20 ct+ as on request.

In practice, a white or specific-color 30 ct request goes like this:

1. You send carat band, shape (with a fallback), color range, clarity floor, and report preference.
2. The desk confirms whether a stone exists, can be sourced, or must be grown.
3. For grown-to-order stones, you ask for the date and the terms in writing before paying.
4. You review photos, 360-degree video, and the report for any shortlist.
5. You pay the pro-forma invoice and receive the stone by insured courier.

There is a practical alternative worth raising with any supplier: two 15 ct stones, or a 25–29 ct stone, can sometimes meet the design more quickly than a single 30 ct. Ask for ranges.

Which Report Should a 30 Carat Stone Carry?

Liora's Big Diamonds page says big stones are supplied with an IGI report as standard and that GIA can be arranged, adding time and cost. The report number should be verified on the laboratory's own website. Our IGI certification guide and the broader laboratory-grown certification article cover the difference; for single stones above 3 ct, the choice should be made before the shortlist, because a GIA submission changes the timeline. Check that the report states the growth method (here, CVD) and any post-growth treatment, because the GIA 34.59 ct case shows annealing can be part of how a color is achieved. The CVD supplier guide and HPHT supplier guide explain each process for buyers.

Shipping, Payment and First-order Checks With Liora Diamond

Liora's country pages for Hong Kong, Switzerland, the United States and the UAE each say stock usually ships within a few business days of payment by insured valuables courier, with payment by bank transfer against a pro-forma invoice and duty paid by the importer of record. The Hong Kong, Switzerland, and US pages describe stones from about 3 ct to 30+ ct, which matches the 30 ct tier. Read the shipping policy for terms. Note those timings apply to stock; a grown-to-order stone follows the date the desk confirms.

Before a first order at this value, confirm four things in writing:

1. That the stone you saw on video is the stone on the invoice
2. The original report travels with it
3. Who clears customs
4. What happens if the stone is unavailable after payment

Liora's pages do not state a hold or reservation period, so ask rather than assume. For a US view, see the guide for U.S. jewelers, and for Gulf buyers, the Dubai supplier guide.

How to Write the Request

A good 30 ct brief fits in a short WhatsApp message: shape and fallback shape, carat band (for example 28–32 ct), hue and grade range, clarity floor, whether modifiers are acceptable, report, quantity, setting seat dimensions, destination and importer of record. The full field list is in our RFQ template for big lab-grown diamonds. If you plan finished pieces, the B2B jewelry page is the route, and wholesale covers parcels.

Terms to note

Liora supplies businesses only, and we're committed to that: "Please don't enquire for single items under US$2,000", and a 30 ct stone is far above that, but read the trade terms before you enquire. The largest stone was 30.16 ct. If you need more than that, ask for it as a sourcing request; do not treat any larger size as in stock.

Request a stone shortlist with your shape, carat band, color range, and clarity floor, or browse the Big Diamonds page first.

FAQ

1. Do 30 carat lab-grown diamonds exist?

Yes. Liora Diamonds have three stones over 30 ct (30.16, 30.09, and 30.08 ct), all pink-family fancy colors with IGI reports and CVD growth. They are rare and stock changes, so confirm availability with the trade desk before you plan around one.

2. What is the largest lab-grown diamond?

GIA reported a 34.59 ct CVD emerald cut (G color, VS2) in May 2023. Jeweller Magazine reported a 75.33 ct IGI-graded stone shown at JCK in June 2024. The 75.33 ct figure comes from one trade report that we have not independently verified, and records change, so check the latest announcements before quoting either.

3. Are 30 carat lab-grown diamonds always CVD?

Not as a rule. Every 30 ct+ stone in Liora's listing was CVD, and the GIA 34.59 ct stone was CVD with post-growth HPHT annealing. HPHT-grown stones also exist. Check the report, which states the growth process and any treatment, rather than assuming.

4. How big is a 30 carat laboratory-grown diamond in mm?

It depends on the shape. A measured 25.07 ct heart in Liora's catalogue is 18.28 × 20.35 × 9.01 mm, and scaling those proportions gives roughly 19.4 × 21.6 × 9.6 mm at 30 ct. That is an estimate, not a real stone; ask the desk for the actual measurements and report.

5. How long does a 30 carat white stone take to source?

Liora does not publish a timeline for white stones above 20 ct. Its Big Diamonds page says larger or exact-spec stones are grown to order and that a date is given before you commit. Ask for that date in writing, with the terms, before paying.

6. Is there a minimum order for a 30 carat stone?

Liora is trade-only, and its pages say trade orders must be US$2,000 or more. A 30 ct stone is well above that. The wording varies between pages (per item, per order), so confirm with the desk.