Lab Grown vs Mined Diamonds: The 2026 Australian Comparison

A lab grown diamond and a mined diamond are the same material: the same carbon lattice, the same 10 on the Mohs scale, the same fire, graded by the same laboratories on the same 4Cs. A gemmologist cannot separate them by eye. The price gap is the only large difference. Here is what that means for an Australian buyer in 2026.

A note on where we stand. We make rings in a Southbank studio in Melbourne and sell lab grown diamond and moissanite. We do not sell mined diamonds, so read the parts where our interests line up with our conclusions with that in mind.

At a glance

Swipe across the table to see every column.

Where each one comes from

A mined diamond crystallised in the earth's mantle and reached the surface in a kimberlite eruption. Australia's Argyle mine closed in 2020, taking most of the world's pink diamond supply with it.

A lab grown diamond is made one of two ways. CVD floods a vacuum chamber with carbon rich gas and deposits carbon onto a seed plate, layer by layer. HPHT reproduces mantle pressure and temperature in a press. Both take weeks. Both produce diamond, not a substitute. The growth method affects how the stone is screened and inscribed. It does not affect how it looks on a hand.

Grading is identical, and cut matters most

Both go to the same labs and come back with the same report: carat, colour on the D to Z scale, clarity from FL to I, and a cut grade. Because lab grown is affordable, retailers push D colour and VVS clarity as if those were the point. They are not. On a hand, in normal light, a G colour VS2 round with an excellent cut is indistinguishable from a D VVS1, and the saving buys size or a better setting. The exception is step cuts: emerald and asscher hide nothing, so spend on clarity there.

Cut grade is the one line on the certificate that changes how a stone looks across a room. Buy that first. Every stone we set is IGI certified and laser inscribed with its report number, which you can check on IGI's own database. If you are new to reports, start with the 4Cs explained.

Price

At the same carat, colour, clarity and cut, a lab grown diamond costs a fraction of a mined one, and the gap has widened since 2020 as lab production scaled. A budget that buys a well cut stone under a carat in mined buys comfortably over a carat in lab grown, with better colour and a heavier setting.

Spend the difference on cut grade first and the setting second, because the setting is what fails. Thin cast bands and unfinished claws wear through inside five years of daily wear, and no certificate protects you from that. Our lab grown designs start at AU$1,350 in the lab grown diamond collection.

The environmental question, honestly

Lab grown is marketed as the ethical choice. That is often true and not automatically true. Growing a diamond means running a reactor at high temperature for weeks, so the footprint is roughly the footprint of that electricity. Most production sits in India and China on grids that are still partly coal fired. A stone grown on hydro or verified renewables is genuinely low impact; almost no retailer can tell you which one you are holding. Ask who audited any carbon neutral claim.

Mining moves large volumes of earth and water per carat and disturbs land for decades. It also employs a great many people. The Kimberley Process addresses conflict financing only; it does not certify labour or environmental practice.

What we claim and nothing more: our delivery is carbon offset, insured and signature required. We will not tell you the ring itself is carbon neutral, because we cannot prove it.

Resale, for both

Lab grown diamonds do not hold their retail value. Prices have fallen since 2020, so a stone bought three years ago competes against a cheaper new one. Mined diamonds do not hold their retail value either. In both cases the second hand buyer pays for stone and metal at replacement cost; the GST, labour, marketing and margin do not come back. The narrow exceptions are fancy colours, especially Argyle pinks, and signed period pieces. Almost no engagement ring sold in Australia is either. If value retention matters, get the ring valued and listed on your contents insurance rather than treating it as an asset.

Who should buy which

For the third option, read moissanite vs diamond. The moissanite collection starts at AU$800.

Quick answers

Can a jeweller tell a lab grown from a mined diamond?
Not by eye or loupe. It takes spectroscopic screening, which is why the laser inscription and matching report matter. Always ask for the report number.

Do lab grown diamonds go cloudy?
No. They are diamond. A dull ring is soap and sunscreen under the stone, which comes off with warm water, detergent and a soft toothbrush.

Is lab grown cheaper because it is lower quality?
No. It is cheaper because supply is not constrained. Same grading scale, same material.

What certificate should I insist on?
IGI or GIA, with the report number inscribed on the girdle. Check it on the lab's website before you pay.

Last updated September 2026. Pricing in AUD from our Melbourne studio. All lab grown diamonds IGI certified and laser inscribed.