Moissanite vs Diamond: The 2026 Australian Buyer's Guide

Moissanite versus diamond is not about which is better. It is about which one suits what you want to wear and what you want to spend. We set both moissanite and lab grown diamond every week in our Southbank studio. Here is the short version.

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At a glance

Swipe across the table to see every column.

1. Sparkle

Moissanite has a refractive index of 2.65, diamond 2.42. In practice moissanite breaks light into more colour, the rainbow flashes jewellers call fire. Diamond is quieter, with white light return and less colour. Some people love the extra life in moissanite, others want the more understated diamond look. Neither is wrong.

Two things change how much fire you see. Cut quality: a premium grade moissanite shows refined colour, a cheap one looks like a disco ball. And size: a 0.5ct moissanite reads almost like a diamond, a 2ct moissanite shows far more fire than a 2ct diamond.

2. Durability

Moissanite is 9.25 on the Mohs scale, diamond 10. Both are harder than sapphire and more than tough enough for daily wear, gym, beach and dishes included. After 30 plus years a moissanite may show micro scratches under a 10x loupe. To the naked eye, rings we have serviced after 15 years still look new.

The real durability risk on either stone is chipping at sharp points: the tip of a pear or marquise, the corners of an emerald cut. If you have an active job, oval or round cuts with no exposed points are the safer choice.

3. Cost

The price gap is the biggest practical difference between the stones. For a 1.5ct centre stone in an 18K gold ring:

• Moissanite ring: $2,000 to $3,500
• Lab grown diamond ring: $3,500 to $5,500
• Mined diamond ring: typically $10,000 or more at Australian retail. We do not sell mined stones, so treat that as a market reference rather than our quote

The saving over a mined diamond is a house deposit contribution, a longer honeymoon, or a year of mortgage payments. Our own orders split roughly evenly between moissanite and lab grown diamond, so there is no wrong answer here, only the trade-off between extra fire and diamond chemistry. We have hundreds of designs under AU$2,000, all with premium grade stones, certification and a lifetime warranty.

4. Ethics and sourcing

Moissanite is grown from silicon carbide by a small number of certified producers, with a clear record from synthesis to setting. Lab grown diamond is chemically identical to mined diamond, grown in weeks rather than dug up. Neither involves mining. The Kimberley Process covers conflict financing for mined stones, but it does not certify labour conditions or environmental practice, and mining has a large footprint per carat.

One honest caveat on lab grown diamond: its footprint depends on the electricity that ran the reactor, and most retailers cannot verify that. It avoids mining, it is not automatically carbon neutral.

5. Resale

Do not buy an engagement ring as an investment, in any material. Second hand buyers pay for the stone and the metal at replacement cost. The GST, labour, certification and margin in the retail price do not come back. Moissanite and lab grown diamond both resell poorly. Mined diamond resells a little better and still well below what you paid.

What we do instead: a lifetime upgrade credit. Bring back any ring you bought from us and we credit the full original purchase price toward a new one.

6. Lab grown diamond, the middle option

If you want diamond chemistry, IGI certification and diamond's more subtle sparkle, at 40 to 60% of a mined price, lab grown diamond is the answer. Diamond remains the more popular choice in the wider market, and about half of our own customers pick it. It costs 1.5 to 2 times an equivalent moissanite and you do not get the extra fire. Our full comparison is in moissanite vs lab grown diamond, and the lab grown range starts at AU$1,350 in the lab grown diamond collection.

How to decide

Whichever stone you pick, treat the setting as a separate decision. Solitaire, hidden halo, trilogy or pavé changes the look as much as the stone does. The ring builder lets you combine any stone with any setting.

Quick answers

Is moissanite a real diamond?
No. Moissanite is silicon carbide, diamond is carbon. They look similar, but a jeweller can tell them apart with a refractometer or a dual tester.

Will moissanite pass a diamond tester?
A basic thermal tester reads moissanite as diamond. A modern dual tester correctly identifies it.

Does moissanite go cloudy or yellow?
No. Modern D to E colour moissanite is colour stable for life. Any dull ring is usually soap and sunscreen under the stone, which washes off.

Will people know it is not a diamond?
Not by looking. Even most jewellers need a loupe or a tester.

Can I upgrade later?
Yes. Full original purchase price credited toward any higher value ring, for life.

Last updated September 2026. Moissanite and lab grown diamond pricing from our Melbourne studio in 2026 AUD. Mined diamond pricing is a general Australian retail reference, not a quote. Moissanite graded per GRC, diamonds per IGI.