The Complete Lab Grown Diamond Buyer's Guide 2026
How they're made, how they compare, which shapes and sizes offer the best value, what the IGI certificate really tells you — and our pick of the finest lab grown diamonds available in Australia right now.
Lab grown diamonds have moved from novelty to mainstream in the space of a decade. In Australia, they now account for a significant and growing share of all diamond engagement rings sold — and the reasons are not hard to understand. A lab grown diamond is physically, chemically and optically identical to a mined diamond. It has the same hardness, the same refractive index, the same fire and brilliance. What it does not have is a century of geological formation time — or the corresponding price tag. This guide tells you everything you need to know before you buy.
How Lab Grown Diamonds Are Made
There are two methods of producing gem-quality lab grown diamonds, and both begin with the same raw material: carbon.
The original method, developed in the 1950s. A diamond seed is placed in carbon under enormous pressure (around 1.5 million PSI) and temperatures exceeding 1,400°C, replicating the conditions deep within the earth's mantle. Carbon crystallises around the seed, growing a rough diamond over days to weeks. HPHT diamonds often have a characteristic cubic or octahedral growth shape.
The more modern method, now dominant for gem-quality stones. A diamond seed is placed in a chamber filled with carbon-rich gas (typically methane). Microwave energy or another ionisation source breaks the gas molecules, and carbon atoms rain down onto the seed, building up layer by layer like a crystal snowfall. CVD diamonds typically grow in flat plates and are then cut and faceted like any mined rough. CVD allows for greater control of the final stone's properties.
Both methods produce genuine diamond. The certificate will typically indicate the growth method (CVD or HPHT), but this has no bearing on the quality or appearance of the finished stone — what matters is how well it was grown and cut.
Natural vs Lab Grown: The Honest Comparison
| Factor | Natural Diamond | Lab Grown Diamond |
|---|---|---|
| Chemical composition | Pure carbon (crystalline) | Pure carbon (crystalline) |
| Hardness (Mohs) | 10 | 10 |
| Refractive index | 2.42 | 2.42 |
| Fire & brilliance | Identical | Identical |
| Price per carat | High; rises steeply with size | Significantly lower; 60–85% less |
| Resale value | Stable long-term market | Lower resale; market still developing |
| Rarity | Finite; formed over billions of years | Producible on demand |
| Certification | GIA, IGI | IGI (standard), GIA (available) |
| Fancy colours | Extremely rare, very expensive | Accessible; wide colour range |
| Ethical sourcing | Requires verification (Kimberley Process) | No mining; lower land impact |
The practical implication for buyers: if you want the largest, most visually impressive diamond your budget can stretch to, lab grown is the answer. If you are buying as a long-term investment or place significant value on geological rarity, natural is the choice. Most buyers in 2026 are choosing lab grown for size and quality, and natural for sentiment and legacy.
Reading Your IGI Certificate
The International Gemological Institute (IGI) is the leading certifying body for lab grown diamonds worldwide. Every lab grown diamond in our collection carries an IGI certificate, which reports the following:
- Shape and cutting style — e.g. "Round Brilliant," "Oval Modified Brilliant"
- Measurements — diameter and depth in millimetres
- Carat weight — to two decimal places
- Colour grade — D through Z for colourless; or "Fancy" designation for coloured stones
- Clarity grade — FL, IF, VVS1/2, VS1/2, SI1/2, I1/2/3
- Cut grade — Excellent, Very Good, Good, Fair, Poor (for rounds)
- Polish and symmetry — assessed independently
- Fluorescence — None, Faint, Medium, Strong, Very Strong
- Growth method — CVD or HPHT
- Laser inscription — IGI report number inscribed on the girdle
The Best Lab Grown Diamond Shapes — and Why
Every shape is available in lab grown, but some offer better value relative to their natural counterparts than others. Here is our assessment of each major shape in the lab grown context.
Round Brilliant — Unbeatable Value Uplift
The price differential between natural and lab grown is widest for round brilliants, because round naturals command a significant premium due to the waste involved in cutting a round from rough. This means lab grown rounds offer the greatest relative value. Our 2.09ct round D VS1 Excellent IGI and 2.01ct round D VVS2 Ideal IGI are both outstanding stones at sizes that would be stratospheric in natural form. The 3.61ct round E VVS2 Ideal IGI is simply one of the finest lab grown rounds we carry.
Oval — The Shape That Benefits Most from Scale
Oval lab grown diamonds are, in our view, one of the greatest value propositions in all of jewellery. The elongated shape means a 2ct oval has a face-up surface area closer to a 2.5ct round — and in lab grown, a 2ct oval is extremely accessible. Our 2ct oval E SI1 IGI is a beautifully proportioned entry-level option, the 3.11ct oval G SI1 IGI occupies the sweet spot between size and budget, the 3.69ct oval G SI1 IGI is a genuinely impressive stone, and the 3.74ct oval F VVS2 IGI steps up to excellent clarity. For those who want the absolute pinnacle, the 1.85ct oval D IF IGI is internally flawless — the highest possible clarity grade.
Cushion — Warm Brilliance at Exceptional Size
Cushion cut lab grown diamonds allow buyers to access the warm, romantic "crushed ice" sparkle of the cushion at sizes previously reserved for very significant budgets. The 1.58ct cushion modified D SI1 IGI is a top-colour cushion at an accessible price. The 1.83ct cushion F VS1 IGI steps up to VS clarity. The 3ct princess D VVS1 IGI shows what lab grown production can deliver — a three-carat princess at the very top of the colour and clarity scale is extraordinary by any measure.
Emerald Cut — Step-Cut Depth at Lab Grown Prices
The emerald cut's demand for high clarity makes it particularly compelling in lab grown form, where top clarity grades are more accessible. Our 2.08ct emerald E VS1 IGI is a balanced, beautiful stone. The 2.10ct emerald D VVS1 IGI is near the top of the quality scale, and the 2.12ct emerald G IF IGI is internally flawless — the perfect clarity for a step-cut. For those wanting to go larger, the 3.08ct emerald D VVS1 IGI is simply spectacular, and the 5.02ct emerald F VVS1 IGI is a landmark stone — five carats in an emerald cut commands a room.
Radiant — Bold Geometry, Maximum Sparkle
Radiant lab grown diamonds offer the combination of a strong geometric outline and brilliant-cut sparkle that makes them ideal for bold, modern engagement rings. The 1.70ct radiant D VVS2 IGI is top tier in both colour and clarity. The 2.51ct radiant D VVS2 IGI takes it further — a compelling size at a compelling price for the quality offered.
Marquise — The Shape That Looks Largest of All
In lab grown form, the marquise's natural face-up advantage is amplified by the ability to go larger than would be practical in natural. The 2.13ct marquise F VVS2 IGI is a refined, high-clarity stone. The 2.46ct marquise F VVS2 IGI is even more imposing, and the 4.56ct marquise F SI1 IGI is one of the most dramatic loose diamonds in our collection.
Princess & Asscher — Step and Brilliant in Square Form
For square shapes, lab grown is particularly persuasive. The 2.08ct princess D VVS2 IGI is a very fine stone, and the 2.23ct princess D VVS2 IGI adds just a fraction more size at the same quality level. For Asscher cuts — which, like emerald cuts, benefit greatly from high clarity — the 1.72ct Asscher D VVS2 IGI is an exceptional stone, and the 1.85ct Asscher D VVS2 IGI steps it up further.
Fancy Coloured Lab Grown Diamonds — A Category of Their Own
The ability to grow fancy coloured diamonds reliably and at scale is perhaps the most transformative thing lab grown technology has brought to jewellery. Colours that exist in natural form only as extraordinary rarities — vivid pink, vivid blue, vivid green, intense yellow — are now accessible in meaningful carat weights.
Our 1.79ct fancy vivid pink Asscher lab grown VVS2 IGI is one of the most remarkable stones in our current collection — the Asscher cut's depth and the saturation of vivid pink are extraordinarily beautiful together. The 2.10ct emerald F SI1 IGI in white, paired against our coloured stone offerings, shows how wide the range has become. For truly rare natural fancy colour, the 1.59ct fancy yellow natural cushion VVS2 GIA and the 0.71ct fancy dark orangey-brown natural cushion VS2 GIA are exceptional examples of how unusual natural fancy colours can be — these coloured stones are formed by specific trace elements or structural anomalies that occur during geological formation, making each one entirely unique.
Lab Grown Diamonds Already Set — Ready to Wear
Beyond the loose stone market, several of our preset ring designs are built around specific lab grown diamonds. These offer the convenience of a ready-to-wear piece with the transparency of a disclosed lab grown centre stone.
The 2ct lab grown oval hidden halo engagement ring in 18k white gold is a particularly popular design — the hidden halo elevates the 2ct oval magnificently. The 2ct lab grown oval with pear-shape side stones in 18k white gold is a more distinctive take — the pear side stones add movement and rarity to the design. The 1ct GIA certified oval engagement ring in 18k white and yellow gold two-tone setting brings a vintage-inspired two-tone treatment to a clean four-claw oval design.
Natural Diamonds Under 1 Carat — Quality Without the Premium
Not every buyer wants or needs a large centre stone. For solitaires, stacking rings, or earrings, a smaller natural diamond with excellent grades can be a compelling purchase — you get genuine GIA or IGI certification, geological rarity, and strong long-term value at a price point that is very accessible.
Our 0.57ct round G IF Excellent IGI is Internally Flawless — extraordinary clarity for a natural diamond at well under one carat. The 0.70ct cushion G VVS1 GIA brings the cushion cut's warmth at a budget-friendly weight. The 0.80ct oval D SI1 GIA offers top-colour D in a natural oval — the combination of fine colour and a flattering shape makes this an exceptional stacking ring stone. The 0.86ct round D SI1 Excellent IGI brings top colour and a premium cut grade. For something more unusual, the 0.38ct emerald cut D SI1 GIA is a tiny but exquisitely colour-graded step-cut stone — perfect for a minimal bezel setting. The 0.50ct oval D VS2 VG IGI is an excellent half-carat entry into D-colour natural ovals.
Specialty Pieces and Conversation Starters
Some diamonds in our collection defy easy categorisation. These are for buyers who want something that cannot be found anywhere else.
The 3.02ct fancy brownish-yellow natural cushion SI1 GIA is a remarkable stone — the warm, earthy tone of a natural brownish-yellow in a three-carat cushion is a genuinely striking combination. The 1.02ct cushion modified D VVS1 GIA is about as close to perfection as a natural cushion can come — D colour and VVS1 clarity in a beautifully proportioned stone. The 1.20ct round G IF Excellent IGI is Internally Flawless at over a carat — a stone that will pass the most stringent quality inspection. The 1.01ct round D VVS1 GIA is the classic "one-carat top-tier" natural stone that remains the industry's most coveted benchmark.
Frequently Asked Questions
Will a jeweller be able to tell my diamond is lab grown?
Not with standard gemological tools. The standard refractometer, loupe and microscope cannot distinguish lab grown from natural — both are chemically and optically identical. Specialist equipment (such as De Beers' DiamondView machine, which uses short-wave UV light to examine growth patterns) can make the distinction, and major grading labs use such equipment. For everyday purposes, including appraisals and insurance, the certificate is the disclosure mechanism. All our lab grown diamonds are clearly identified as such on their IGI certificates.
What is the difference between CVD and HPHT lab grown diamonds?
CVD (Chemical Vapour Deposition) and HPHT (High Pressure High Temperature) are the two production methods. CVD now dominates for gem-quality stones because it offers better control over the final product. HPHT is still used, and some HPHT stones are actually post-processed via HPHT to improve their colour grade. In practical terms for a buyer, the growth method has no bearing on the beauty or durability of the finished stone — what matters is the cut, colour, clarity and carat weight reported on the certificate.
Do lab grown diamonds hold their value?
No — and this is the one clear disadvantage compared to natural diamonds. The resale market for lab grown diamonds is currently much less developed than for natural stones, and the rapid decrease in lab grown production costs means that prices have fallen significantly over the past few years. A lab grown diamond should be purchased for the joy of wearing it, not as a financial investment. If long-term value retention is important to you, a natural GIA-certified diamond is the wiser choice.
Which lab grown shapes offer the best visual value?
Oval and marquise consistently offer the greatest face-up size per carat weight of any shape — and in lab grown, where larger sizes are accessible, this effect is dramatic. A 3.69ct oval lab grown will look significantly larger than a 3.69ct round of the same weight. The emerald and Asscher cuts benefit from lab grown's ability to produce top clarity grades cost-effectively — these shapes are almost uniquely suited to lab grown diamonds for this reason.
What clarity grade should I choose for a lab grown diamond?
For round, oval, cushion and other brilliant-cut shapes, VS2 to SI1 is the standard recommendation — inclusions are invisible to the naked eye and you're not paying for clarity that can't be seen. For step-cut shapes (emerald, Asscher), where the open facets act as windows, VS1 or better is recommended. Our 2.10ct emerald D VVS1 IGI is a perfect example of why high clarity matters in emerald cuts — the open table is breathtaking when the clarity grade supports it.
Are fancy coloured lab grown diamonds real fancy coloured diamonds?
Yes. A fancy vivid pink lab grown diamond is a genuine pink diamond — chemically identical to its natural counterpart. The colour is produced by introducing specific elements during the growth process (boron for blue, nitrogen for yellow) or by post-growth treatment (for pink and other colours). The IGI certificate will record the colour as "Fancy Vivid Pink" or equivalent, exactly as it would for a natural stone, with an additional notation confirming the lab grown origin. Our 1.79ct fancy vivid pink Asscher IGI is a certified example of what this looks like in practice.
Browse Our Complete Lab Grown Diamond Collection
Every stone in our lab grown range carries an IGI certificate. Browse loose diamonds across all shapes and sizes, or explore our preset engagement rings featuring lab grown centre stones.
Shop Lab Grown Diamonds