Lab-Grown vs Natural Diamonds in Australia: Price, Value & How to Choose

How natural and lab-grown diamonds are formed

Natural diamonds

Most natural diamonds crystallised deep in the Earth's mantle, roughly 150 kilometres or more below the surface, where extreme heat and pressure allowed carbon to form a tightly bonded crystal structure. Many are estimated to be billions of years old. Volcanic eruptions later carried them towards the surface in magma, forming kimberlite pipes, where they are mined before being cut and polished.

Because every natural diamond grew in its own conditions, each stone carries small internal characteristics that reflect its unique history. Gem-quality natural diamonds of good size, colour and clarity are relatively rare, which is a major reason for their price.

Lab-grown diamonds

Laboratory-grown diamonds (also called laboratory-created or synthetic diamonds) are produced in specialised facilities. There are two main methods:

• HPHT (high pressure, high temperature): recreates the intense heat and pressure found deep in the Earth.
• CVD (chemical vapour deposition): grows diamond from carbon-containing gas onto a diamond seed, at much lower pressures.

Instead of billions of years, growth takes a comparatively short time, depending on the method and the size of the stone. After growth, the rough crystal is cut and polished in the same way as a natural diamond.

Both are diamonds, not simulants

A common misunderstanding is that lab-grown diamonds are imitations. They are not. A lab-grown diamond shares the same crystal structure of bonded carbon atoms as a natural diamond, which gives it nearly the same chemical, optical and physical properties. The difference is its origin, not what it is made of.

Diamond simulants are different materials that only look similar:

• Cubic zirconia (CZ) is a synthetic material made from zirconium dioxide. It is softer and more brittle than diamond, and is readily identified by gemmological testing.
• Moissanite is silicon carbide. It is hard and durable, but it is doubly refractive and disperses light differently from diamond, so it can show more coloured flashes and, in some stones, a slightly greenish or greyish tint.

When you buy a diamond, it should always be described clearly as either natural or laboratory-grown. A reputable jeweller will disclose this in writing, and a grading report from a major laboratory such as GIA or IGI will identify a laboratory-grown diamond as such.

Lab-grown vs natural: side-by-side comparison

Swipe left or right to compare diamonds.

Grading reports: how GIA and IGI differ

An independent grading report is one of the most important documents when buying any diamond. It confirms the stone's origin and describes its characteristics, so you can compare diamonds fairly. You can learn more in our guide to diamond certificates.

For natural diamonds, the familiar 4Cs apply: cut, colour, clarity and carat weight. For lab-grown diamonds, the two laboratories you are most likely to see now take different approaches:

• GIA (Gemological Institute of America): since 1 October 2025, GIA no longer uses the grading terms created for natural diamonds when describing eligible colourless to near-colourless lab-grown diamonds. Instead, its quality assessment classifies each eligible stone as Premium or Standard. Stones that do not meet GIA's minimum criteria do not receive an assessment. Assessed stones are laser-inscribed on the girdle with "Laboratory-Grown" and the GIA assessment number.
• IGI (International Gemological Institute): continues to grade lab-grown diamonds using the traditional 4Cs, so an IGI report shows a colour grade, clarity grade and, for round brilliants, a cut grade, together with the stone's laboratory-grown origin. IGI reports also commonly note the growth method (HPHT or CVD).

Older reports may look different. A GIA lab-grown report issued before October 2025, for example, will not use the Premium/Standard format, and earlier report designs from either laboratory may present information differently. Always read the report itself rather than assuming its format.

Whichever laboratory graded the stone, check that:

1. The report clearly states whether the diamond is natural or laboratory-grown.
2. The report number matches the diamond. Diamonds are commonly laser-inscribed on the girdle with the report number, which you can match to the report.
3. You compare like with like. A GIA Premium or Standard assessment cannot be directly compared with an IGI colour and clarity grade, and grading standards are not always identical between laboratories.

Price, long-term value and resale

Price is usually the first reason couples consider lab-grown diamonds. For a similar carat weight, colour and clarity, a lab-grown diamond typically costs considerably less than a natural diamond. That difference can allow a larger stone, a higher colour or clarity grade, or more budget for the setting.

Long-term value is just as important to understand:

• Lab-grown diamonds: prices have fallen significantly in recent years as production has increased, and the resale market for them is limited.
• Natural diamonds: there is a more established resale market. However, natural diamond prices also move with market conditions, and resale offers are usually well below the original retail price.

Neither type has a guaranteed resale value, and neither offers guaranteed investment returns. No one can reliably predict future diamond prices. It's best to think of an engagement ring as something you buy to wear and enjoy, not as a financial asset.

Why cut quality matters for both

A diamond's cut determines how it interacts with light. A well-cut diamond returns light as brightness (white light), fire (flashes of colour) and scintillation (sparkle as it moves). A poorly cut diamond can look dull or glassy, regardless of whether it is natural or lab-grown, or how high its colour and clarity grades are.

Because lab-grown diamonds cost less, it can be tempting to prioritise size above everything else. A widely used approach for either type is to prioritise cut quality first, and then balance carat, colour and clarity within your budget. If you are considering a round diamond, our round brilliant engagement rings are a good place to compare styles; for an elongated look, explore oval engagement rings.

Our perspective at GoldeNet

GoldeNet Australia has specialised primarily in natural diamonds for approximately 20 years. We also source and sell laboratory-grown diamonds, and we can offer competitive pricing on both.

Eli Butbul's view is that lab-grown diamonds are an excellent option for many couples, particularly those working with a limited budget. They offer genuine diamond characteristics and can provide a larger or higher-specification stone for less money. At the same time, lab-grown diamond prices have fallen significantly, and Eli does not expect them to retain their purchase value as well as comparable natural diamonds. Natural diamonds generally have a more established resale market, but they can also lose significant value after purchase.

Our advice is therefore simple: choose the diamond that suits your budget, the look you love, your personal preferences and your expectations, and go in with a clear understanding of how each type may hold its value.

How to choose: practical advice for Australian couples

1. Set your total budget first. Include the setting, any wedding band and insurance, not just the centre stone. Our guide to setting an engagement ring budget can help.
2. Decide what matters most. If size and specification for the money are the priority, lab-grown is worth serious consideration. If natural origin, rarity and a more established resale market matter to you, natural may suit you better.
3. Compare like with like. Compare diamonds of a similar shape, cut quality, carat, colour and clarity, graded by the same laboratory and in the same report format where possible.
4. Always get a grading report that states the diamond's origin, and make sure the stone matches the report.
5. See diamonds side by side. Comparing stones in person, or with high-quality images and videos, is the best way to judge appearance.
6. Get clear disclosure in writing. Your receipt and documentation should state whether the diamond is natural or laboratory-grown.
7. Ask about insurance and valuation. Make sure your insurer knows exactly what you have bought.

You can start exploring certified natural diamonds and loose laboratory-grown diamonds online, or design your own engagement ring by choosing a setting first.

Frequently asked questions

Are lab-grown diamonds real diamonds?

Yes. Lab-grown diamonds share the same crystal structure of bonded carbon atoms as natural diamonds, giving them nearly the same chemical, optical and physical properties. They differ in origin, not material. They are not the same as cubic zirconia or moissanite, which are different materials made to look like diamond.

Can you tell a lab-grown diamond from a natural diamond by looking at it?

Generally, no. By eye, a lab-grown diamond and a natural diamond of similar quality can be indistinguishable. Identifying a diamond's origin requires advanced laboratory instruments, which is why an independent grading report stating the origin is so important.

Do lab-grown diamonds hold their value?

Lab-grown diamond prices have fallen significantly in recent years, and their resale market is limited. Natural diamonds have a more established resale market, but their prices also move and resale offers are usually below the original retail price. Neither type has a guaranteed resale value, and neither offers guaranteed investment returns.

What is the difference between GIA and IGI reports for lab-grown diamonds?

Since 1 October 2025, GIA classifies eligible colourless to near-colourless lab-grown diamonds as Premium or Standard rather than giving traditional colour and clarity grades. IGI continues to grade lab-grown diamonds using the traditional 4Cs. Because the formats differ, compare diamonds graded by the same laboratory where possible, and check that the report clearly states the diamond's origin.

Does GoldeNet sell lab-grown diamonds?

Yes. GoldeNet Australia specialises primarily in natural diamonds, and we also source laboratory-grown diamonds at competitive prices. We can prepare a personalised comparison of natural and lab-grown options within your budget. Arrange an appointment at our Melbourne showroom, or contact us online.

Related reading

• What to look for when buying a certified diamond in Australia
• How to choose between oval and round engagement rings
• Diamond education guides