Lab-Grown Diamonds vs Natural Diamonds: The Australian Guide

Lab-grown diamonds vs natural diamonds: what is actually different?

Chemically, physically and optically, there is no difference. Both are pure carbon arranged in the same cubic crystal lattice. Both score 10 on the Mohs scale (the 1–10 scratch-hardness scale), both bend light by the same amount (a refractive index of 2.42) and both split white light into colour by the same amount (dispersion of 0.044). Side by side, a trained gemmologist cannot tell them apart by eye or under a 10× loupe.

What differs is origin, and everything that follows from it: how the stone was formed, the tiny growth features inside it, what the report says, what it costs and what it is worth later. Our complete lab-grown diamonds guide covers the lab side in more depth, and the jewellery glossary explains any term you meet along the way.

Day-to-day wear is identical too. A lab-grown diamond chips, scratches and collects grease exactly like a natural one, so the cleaning and checks are the same; see caring for a lab-grown diamond for the routine.

Are lab-grown diamonds real diamonds?

Yes. A lab-grown diamond is a real diamond, not an imitation. The word that matters is simulant: a stone that only looks like diamond but is a different material. Cubic zirconia (Mohs 8–8.5, refractive index about 2.15) and moissanite (Mohs 9.25, refractive index about 2.65) are simulants. A lab-grown diamond is not.

So the honest framing is natural diamond versus lab-grown diamond, both real, with different origins. Our page on whether lab-grown diamonds are real diamonds goes through the definitions, and lab-grown diamond vs cubic zirconia shows how differently a simulant behaves over years of wear.

Equally, a natural diamond is not an investment, and a lab-grown diamond is not fake. Both are beautiful, durable gems; they simply suit different priorities.

How are natural and lab-grown diamonds made?

Natural diamonds crystallised roughly 150–200 km below the surface, at around 900–1,300°C and enormous pressure, mostly between 1 and 3.5 billion years ago. Volcanic eruptions carried them up in kimberlite pipes, where they are mined today. Read how natural diamonds form for the full journey.

Lab-grown diamonds are made by one of two methods. HPHT (high pressure, high temperature) recreates mantle conditions in a press, dissolving carbon in molten metal so it crystallises onto a small diamond seed. CVD (chemical vapour deposition) breaks down a carbon-rich gas such as methane in a low-pressure chamber, so carbon atoms settle layer by layer onto a thin diamond seed plate. Both take weeks rather than aeons. Our guide to the HPHT and CVD growing methods compares them.

Many CVD diamonds come out of the reactor slightly brown or grey and are then heated under pressure to improve their colour. This post-growth treatment is permanent and should be noted on the report. CVD layering can also leave faint internal banding; CVD growth striations explains when it matters (rarely) and when it does not.

Can you tell a lab-grown diamond from a natural one?

Not by eye, and not with a basic tester. Standard thermal testers read both as diamond, because both conduct heat the same way. Some HPHT lab-grown diamonds contain a trace of boron that conducts electricity, which can confuse a combined diamond–moissanite tester. Our articles on what a handheld diamond tester can and cannot tell and why lab-grown stones test as diamond go into the detail.

Gem laboratories confirm origin with equipment that reads how the crystal grew:

• Spectroscopy: infrared and photoluminescence readings show whether nitrogen is present and how it is arranged. Most natural diamonds are Type Ia; most lab-grown are Type IIa.
• UV fluorescence imaging: under deep ultraviolet light, CVD stones often show fine parallel growth layers and HPHT stones show a cross-shaped (cuboctahedral) pattern. Natural stones show irregular, concentric growth.
• Inclusions: HPHT diamonds can contain tiny metallic flux inclusions; natural stones contain mineral crystals such as garnet or olivine.
• Surface features: an indented natural, a remnant of the original crystal skin left on the girdle, can support natural origin, especially if it shows natural growth marks such as trigons, but a laboratory still confirms it.

Our full explainer on how gem laboratories identify origin covers each instrument.

What does a lab-grown diamond grading report show?

Every diamond of meaningful size should come with an independent report, and for a lab-grown stone the report is also your proof of disclosure. Most lab-grown diamonds in Australia are graded by IGI; GIA grades both types, and its lab-grown report format has changed in recent years. Our comparison of natural and lab-grown report formats shows sample layouts.

Because lab-grown production can be controlled, near-colourless grades are common, so read lab-grown colour grades before paying extra for D or E. Cut still varies widely between producers; our note on cut quality in lab-grown stones explains what to check.

How much do lab-grown and natural diamonds cost in Australia?

This is where the two part ways. Lab-grown diamonds cost much less than natural diamonds of the same size and grade, and the gap has widened as production has grown. The figures below are approximate loose-stone ranges for well-cut round brilliants, G–H colour and VS clarity, and they move quickly.

Natural prices climb steeply with size because large rough is genuinely scarce; see how natural rarity climbs with size. Lab-grown prices rise far more gently, which is why many people choose a larger lab-grown centre stone for the same budget.

The same choice applies to small stones. Lab-grown melee (tiny accent diamonds under about 0.20 ct) is now common in halos and pavé bands, and should be disclosed just like a centre stone. Our guide to lab-grown melee in pavé and halo rings covers matching and disclosure.

Do lab-grown diamonds hold their value?

Not in the way people hope. Lab-grown wholesale prices have fallen substantially over the past several years and are likely to keep moving, so resale value is very limited. Natural diamonds have an established secondary market, but you will usually be offered well below what you paid at retail, often a fraction of it.

The honest advice: neither type should be bought as a financial asset. Buy the stone you will enjoy wearing, at a price that feels right for you today.

Insurance is still worth having for both. Insure for replacement cost and update the valuation every few years, because lab-grown replacement costs can fall while natural costs can rise. Our page on insuring a lab-grown diamond explains what insurers ask for.

What do Australian rules say about selling lab-grown diamonds?

Under the Australian Consumer Law, businesses must not engage in misleading or deceptive conduct or make false representations about what goods are made of or where they come from. For diamonds, that means a lab-grown stone must be disclosed clearly every time: on the tag, the website, the invoice and the report.

• Clear wording: 'lab-grown', 'laboratory-grown' or 'laboratory-created diamond'.
• Unclear or risky: 'real', 'genuine' or a trade name on its own, without saying lab-grown.
• Never acceptable: calling a lab-grown diamond 'natural', or a simulant such as cubic zirconia or moissanite a 'diamond'.
• Paperwork: the invoice should state origin, carat, colour, clarity and the report number.

Overseas, the US Federal Trade Commission updated its jewellery guides in 2018 to recognise lab-grown stones as diamonds as long as their origin is clearly qualified, and many Australian jewellers follow the same wording. Ethical claims need care too: read the careful use of 'conflict-free' before relying on any marketing phrase.

Natural vs lab-created gemstones: does the same apply?

Yes. Coloured gems have been made in laboratories for over a century; lab-created ruby was produced commercially by flame fusion in the early 1900s. Lab-created sapphire and ruby (both corundum, Mohs 9) and lab-created emerald (beryl, Mohs 7.5–8) share the chemistry and optics of their natural counterparts.

The wording rule is the same: a lab-made gem must be called lab-created or synthetic sapphire, ruby or emerald, never just 'sapphire'. The price gap is usually even wider than with diamonds, and identification again relies on a gem laboratory, which looks for curved growth lines, flux residue or gas bubbles that natural stones lack.

Lab-grown vs natural diamonds: which should you choose?

There is no wrong answer, only a choice of priorities. Natural suits people who value rarity and a story that goes back billions of years. Lab-grown suits people who want more size or a higher grade for the money. Working through these steps makes the decision clear:

1. Set your budget and target size. Compare what each option gives you at the same price using the table above.
2. Decide what matters most. Rarity and origin, or size and grade for the money.
3. Insist on an independent report. Check the origin statement, growth method and any post-growth treatment.
4. Match the inscription. Read the girdle inscription under a loupe and confirm it matches the report number.
5. Judge the cut, not just the label. Ask for a 360° video and compare light return between stones.
6. Check the paperwork. The invoice should name the stone as natural or lab-grown in plain words.

Whichever you choose, the setting protects it for decades. GemTrove was founded in 2008, from a family jewellery trade going back to 1984, and every ring is made the same way regardless of what sits in the centre.