Lab-Grown Diamonds: The Complete 2026 Guide

Lab-grown diamonds are real diamonds. They have the same chemical composition (pure carbon), the same crystal structure, the same hardness (10 on the Mohs scale), and the same optical properties as diamonds that come out of the ground. A jeweller cannot tell them apart without specialised equipment. A gemologist cannot tell them apart under a loupe.

The only difference is where they come from. Natural diamonds formed over billions of years deep in the Earth's mantle. Lab-grown diamonds are created in a laboratory in a matter of weeks. The end product is identical.

There are two methods used to create lab-grown diamonds, and both produce gem-quality stones suitable for jewellery.

HPHT (High Pressure High Temperature) recreates the conditions under which natural diamonds form. A small diamond seed is placed in a chamber with carbon material and subjected to temperatures above 1,400°C and pressures of roughly 5 GPa — about 725,000 pounds per square inch. The carbon dissolves and crystallises around the seed, forming a diamond over several days.

CVD (Chemical Vapour Deposition) works differently. A thin diamond seed is placed in a sealed chamber filled with carbon-rich gas (usually methane). The gas is heated to around 800°C using microwave energy, which breaks the gas molecules apart. The carbon atoms rain down onto the seed and bond to it layer by layer, growing the diamond upward like a crystal wafer.

Most lab-grown diamonds sold in Australia today are CVD-grown. CVD tends to produce diamonds with fewer metallic inclusions than HPHT, though both methods can yield excellent results. From a buyer's perspective, the growth method matters far less than the final grading — a well-cut, well-graded diamond is a well-cut, well-graded diamond regardless of how it was made.

Physically and chemically, there is no difference. Both are crystallised carbon with a hardness of 10, a refractive index of 2.42, and the same brilliance and fire. The differences that matter to buyers are practical, not scientific:

Based on our analysis of over 9,400 diamond products from Australian retailers, here are the current price ranges for lab-grown diamonds. These are retail prices including GST for mounted stones (set in rings or pendants), not loose stones.

These prices include the setting (typically 18K gold). The diamond alone accounts for roughly 50–70% of the total price for lab-grown pieces, with the setting and side stones making up the remainder.

Yes. Lab-grown diamond prices have been falling since 2021 and the trend has not stopped. The primary driver is production capacity — India and China have massively scaled up CVD diamond manufacturing, and supply now far exceeds demand.

In 2022, a 1ct round lab-grown diamond retailed for $3,500–$4,500 AUD in Australia. In early 2026, the same stone sells for $1,200–$2,800 — a decline of 40–65% in under four years. Wholesale prices have dropped even faster, with some manufacturers reporting per-carat costs below $100 USD for standard quality.

This has implications for buyers. If you purchase a lab-grown diamond today, it will almost certainly be available for less in 12–24 months. This is not a reason to avoid lab-grown — it just means you should think of it as a purchase for beauty and enjoyment, not as a store of value.

Most lab-grown diamonds sold in Australia are certified by IGI (International Gemological Institute). GIA also certifies lab-grown diamonds but is less commonly used for them in the Australian market.

Both labs grade the same 4Cs — carat, colour, clarity, and cut. However, there is a widely discussed difference in grading strictness. IGI has been known to grade some stones one grade higher than GIA would on colour and clarity. A stone that IGI calls "G colour VS1" might be called "H colour VS2" by GIA.

This matters when comparing prices. Two stones that look identical on paper — both "1ct G VS1" — might not be the same quality if one is IGI-graded and the other is GIA-graded. Always compare stones graded by the same lab.

No — and you should know this before buying. Lab-grown diamonds have minimal resale value, typically 10–15% of what you paid. Some buyers cannot resell them at all. The combination of falling wholesale prices and unlimited supply means there is no scarcity-driven floor on the price.

However, this deserves context. Natural diamonds at retail also lose significant value the moment you walk out of the store. A natural diamond purchased at retail typically resells for 30–50% of the purchase price. The jewellery industry has long maintained the illusion that diamonds are an "investment" — they rarely are for consumers buying at retail markup.

If resale value is genuinely important to you, consider gold jewellery (which tracks the commodity price) or look at natural diamonds in the wholesale range. If you want the best-looking diamond for your budget, lab-grown is the clear winner.

Lab-grown diamonds make sense for buyers who want maximum visual impact for their budget. A $3,000 budget buys a 0.5ct natural diamond or a 1.5ct lab-grown diamond — visually, the difference on your hand is dramatic.

They also suit buyers who prefer a lower environmental footprint (though the full lifecycle comparison is complex), and those who simply don't attach emotional value to the idea of a stone being millions of years old.

Lab-grown diamonds are probably not the right choice if you plan to resell the piece, if you value rarity and tradition, or if you expect the piece to become a family heirloom with appreciating value.

The biggest risk when buying lab-grown diamonds in Australia is overpaying. Because prices vary wildly between retailers — we have seen identical specs priced from $1,200 to $4,500 at different stores — independent price checking is essential.

Here is what we recommend:

1. Know your specs. Before you compare prices, you need to compare like-for-like. The carat weight, colour grade, clarity grade, cut grade, shape, and certifying body all affect price. Lustrumo assigns every diamond an Equivalent Value Class (EVC) so you can compare apples to apples.

2. Check the market. Use our Diamond Price Tracker to see what other retailers charge for the same EVC. If a stone is priced 20%+ above the market average for its class, ask the retailer why.

3. Verify the certificate. Always check the certificate number directly with IGI or GIA. Our Certification Verifier cross-references cert numbers against retailer listings to flag misrepresentation.

4. Use the Deal Checker. Paste any retailer product URL into our Deal Checker for an instant fair value estimate with confidence score.