Moissanite can resemble a diamond at first glance, but it is not a diamond and it is not a laboratory-grown diamond. It is a different gemstone with its own chemistry, optical character, price and story.

Both moissanite and diamond can be durable choices for an engagement ring. The better option depends on what you value: the distinctive rainbow fire and accessible price of moissanite, the geological rarity of a natural diamond, or the diamond material and larger size often available through a laboratory-grown diamond.

This guide compares all three clearly, without pretending they are interchangeable.

What is moissanite?

Moissanite is silicon carbide. Henri Moissan identified tiny natural silicon carbide crystals in material from the Canyon Diablo meteorite in the 1890s. Natural moissanite is extremely rare, so the moissanite used in jewellery today is laboratory-created.

Modern gem-quality moissanite is grown as crystal material and faceted into familiar jewellery shapes. It is a diamond simulant: a gemstone used to create a diamond-like look, but with different physical and optical properties.

What is a diamond?

Diamond is crystalline carbon. Natural diamonds formed deep within the Earth and were transported towards the surface by geological processes. Many are ancient – often billions of years old.

Laboratory-grown diamonds are also crystalline carbon. They are produced using high-pressure, high-temperature (HPHT) or chemical vapour deposition (CVD) methods. They are essentially chemically and optically the same as natural diamonds, but have different origins and growth features that specialised laboratories can identify.

That means a laboratory-grown diamond is a diamond. Moissanite is a different gemstone.

Moissanite vs diamond at a glance

Feature	Moissanite	Natural diamond	Laboratory-grown diamond
Material	Silicon carbide	Crystalline carbon	Crystalline carbon
Origin	Laboratory-created for jewellery	Formed in nature	Grown by HPHT or CVD
Mohs hardness	About 9.25	10	10
Optical character	Strong rainbow fire; often a more ‘disco’ effect	Balanced brightness, fire and scintillation depending on cut	Diamond light performance, depending on cut
Rarity	Manufactured and widely available	Geological rarity varies by quality	Manufactured and widely available
Initial price	Usually lowest	Usually highest for comparable quality and size	Usually below natural diamond
Typical resale position	Limited secondary market	Variable; usually below retail	Variable and affected by changing wholesale prices

Which sparkles more: moissanite or diamond?

The two do not simply differ in the amount of sparkle; they have different optical personalities.

Moissanite has higher dispersion than diamond, so it can produce stronger rainbow flashes. This is often especially noticeable in larger stones and under direct lighting. Some people love that vivid, colourful effect; others find it less diamond-like.

A well-cut diamond usually presents a balance of white brightness, coloured fire, contrast and scintillation. Laboratory-grown and natural diamonds share the optical properties of diamond, so their sparkle is governed primarily by cut and individual quality rather than origin.

Moissanite is also doubly refractive, while diamond is singly refractive. Facet junctions may appear doubled when viewed through some directions under magnification, and this contributes to moissanite’s distinct visual character.

Claims that one stone is categorically ‘more brilliant’ can be misleading because brilliance also depends on cut design, proportions, lighting and how the term is being measured. It is more useful to compare the look side by side.

Does moissanite look exactly like a diamond?

Not exactly. In small stones or casual viewing, the difference may not be obvious to an untrained observer. In larger stones, moissanite’s colourful fire, facet doubling and occasional undertone can make the distinction easier to see.

Modern colourless and near-colourless moissanite has improved considerably, but quality and colour still vary by producer. The important question is not whether it can ‘pass’ as something else. It is whether you genuinely enjoy the way it looks and are comfortable choosing it for what it is.

Colour differences

Diamonds within the normal range are traditionally described using D-to-Z colour grades, with D at the colourless end. Fancy-colour diamonds use a separate system.

Moissanite is sold using manufacturer or seller descriptions such as colourless or near colourless. These terms should not be assumed to be directly equivalent to a GIA D-to-Z diamond grade. Some moissanite can show warm, greenish or greyish undertones, depending on the material, size and lighting.

For laboratory-grown diamonds, reporting terminology depends on the laboratory. Since October 2025, GIA has used Premium and Standard classifications for eligible colourless to near-colourless laboratory-grown diamonds rather than presenting its traditional natural-diamond grading nomenclature in the same way. IGI and other laboratories may use individual colour and clarity grades.

Durability: can both be worn every day?

Yes, both can be suitable for everyday rings, but hardness is only one part of durability.

Diamond ranks 10 on the Mohs hardness scale and is the hardest natural material. Moissanite is commonly listed at about 9.25, making it highly resistant to scratching. The Mohs scale is ordinal, not linear, so the numerical difference should not be interpreted as a simple percentage.

Hardness means resistance to scratching. It does not mean either stone is indestructible. Diamonds can chip, particularly at exposed points, sharp corners or existing vulnerable features. Moissanite can also be damaged. Setting design, craftsmanship, daily activities and maintenance all matter.

Moissanite does not inherently become cloudy with age. Like any frequently worn gemstone, it can accumulate oils, soap and residue that reduce sparkle until cleaned.

Price and long-term value

Moissanite generally costs considerably less than both natural and laboratory-grown diamond at a comparable visual size. Laboratory-grown diamonds generally cost less than natural diamonds of comparable size and quality, although prices change over time.

Price is not the same as value. Natural diamond buyers may value geological rarity, provenance, tradition and established market recognition. Laboratory-grown diamond buyers may prioritise diamond material and visual scale at a lower initial price. Moissanite buyers may value its distinctive fire and affordability.

None should be presented as a guaranteed investment. Most jewellery resells for less than its retail purchase price. Natural diamonds generally have a more established secondary market, but results depend on the individual stone, documentation, brand, condition and market at the time. Laboratory-grown diamond wholesale pricing has experienced significant change, while moissanite typically has limited resale demand.

Choose with a clear understanding of the purchase price and likely ownership experience, not a promise of financial return.

Ethical and environmental considerations

It is not accurate to say that every mined diamond is unethical, or that every laboratory-grown stone automatically has a lower environmental impact. The answer depends on the mine or production facility, energy source, labour practices, traceability and evidence behind the claim.

Moissanite avoids diamond mining, but its manufacture still uses energy and resources. Laboratory-grown diamond production can also be energy-intensive; its emissions vary significantly according to technology and electricity source. Natural diamond impacts and social contributions vary across operations and countries.

Under Australian consumer guidance, broad claims such as ‘sustainable’, ‘eco-friendly’ or ‘minimal environmental impact’ should be specific and supported by evidence. Ask for transparent sourcing information and credible substantiation rather than relying on a category-wide slogan.

At Xennox, we believe the honest approach is to explain what is known about the individual product and avoid making environmental promises that cannot be verified.

Grading reports and disclosure

Natural and laboratory-grown diamonds may be accompanied by independent laboratory reports that identify origin and describe or assess quality. Moissanite may come with a manufacturer or gem report, but it is not graded under the diamond 4Cs as though it were a diamond.

Always confirm:

• whether the stone is natural diamond, laboratory-grown diamond or moissanite
• who issued any report
• whether a report number can be independently checked
• whether the stone has been treated
• what warranty, care and return terms apply

A report is not a monetary valuation, and the word ‘certified’ should not be used as shorthand for guaranteed value.

Which stone is right for your engagement ring?

Choose moissanite if you value:

• a lower initial price
• generous visual size
• strong rainbow fire
• high scratch resistance
• a non-diamond gemstone you genuinely enjoy

Choose a laboratory-grown diamond if you value:

• diamond’s material and optical character
• a larger diamond within a defined budget
• clear laboratory disclosure of origin
• less emphasis on geological rarity

Choose a natural diamond if you value:

• natural origin and geological history
• rarity and traditional significance
• an established diamond market
• the emotional appeal of a naturally formed stone

There is no universally correct choice. There is only the choice that aligns with your values, eye and budget – made with full and accurate information.

How setting design affects the decision

The centre stone is only part of the ring. A fine handmade setting can change its scale, security and overall character.

Solitaire designs place the optical differences between stones front and centre. Halos increase total sparkle and finger coverage. Bezel and low-profile settings can add protection for active wearers. Side diamonds should be selected thoughtfully: pairing diamond accents with moissanite, for example, may reveal differences in colour and sparkle, which can be either appealing or distracting.

The safest design depends on the stone’s shape, dimensions and the wearer’s life. Points and corners need appropriate protection regardless of material.

Compare your options at Xennox

Choosing a centre stone should not feel like taking a side in an argument. It should feel like understanding the differences and recognising what matters to you.

At our Brisbane studio, our gemmologists and diamond specialists can explain natural and laboratory-grown diamond options and help you assess beauty, documentation and value with clarity. If you are comparing those options with moissanite, we can help you understand the practical and visual differences so your decision is genuinely informed.

Xennox has been creating jewellery in Brisbane since 1976. Our rings are made by hand in our workshop, with the setting designed around the stone and the person who will wear it.

Book an engagement ring consultation in Brisbane to compare your options and create something that feels unmistakably yours.

Frequently asked questions

Is moissanite a diamond?

No. Moissanite is silicon carbide. Diamond is crystalline carbon. Laboratory-grown diamond is diamond; moissanite is a different gemstone.

Can a jeweller tell moissanite from diamond?

A trained professional using appropriate testing can distinguish them. Some basic thermal testers may give confusing results because moissanite conducts heat well, so suitable instruments and expertise matter.

Does moissanite get cloudy over time?

Moissanite does not inherently cloud with age. Surface residue can make it look dull, and regular cleaning restores its appearance in most cases.

Is moissanite durable enough for an engagement ring?

Yes. Its high hardness makes it suitable for daily wear, although it is not indestructible and still requires a secure setting and sensible care.

Is a lab-grown diamond the same as moissanite?

No. A laboratory-grown diamond is crystalline carbon with essentially the same chemical and optical properties as a natural diamond. Moissanite is silicon carbide and has different optical properties.

Which has better resale value?

Natural diamonds generally have the most established secondary market, but most jewellery resells below retail and no outcome is guaranteed. Laboratory-grown diamond and moissanite resale demand is typically more limited and prices can change substantially.