Lab-Grown Diamond vs Moissanite
A detailed, honest comparison of lab-grown diamonds and moissanite. We cover composition, brilliance, hardness, price, durability, and resale value to help you choose the right stone.
What Is Moissanite?
Moissanite is a gemstone made of silicon carbide (SiC), a completely different mineral from diamond (which is pure carbon). It was first discovered in 1893 by the French chemist Henri Moissan in a meteorite crater in Arizona, and naturally occurring moissanite is extraordinarily rare. Virtually all moissanite sold in jewellery today is lab-created.
It is important to understand that moissanite is not a diamond. It is a distinct gemstone with its own unique set of optical and physical properties. While it is often marketed as a "diamond alternative" due to its high hardness and brilliance, the two materials differ fundamentally in chemical composition, crystal structure, light performance, and market value.
That said, moissanite is a genuinely beautiful stone in its own right. It has remarkable fire (the colourful flashes of light you see when a stone is moved), impressive hardness, and excellent durability. The question is not whether moissanite is "good" — it is — but whether it is the right choice for you compared to a lab-grown diamond.
Composition & Structure: A Fundamental Difference
The most important distinction between lab-grown diamonds and moissanite is that they are entirely different materials. A lab-grown diamond is pure crystallised carbon, with atoms arranged in an isometric (cubic) crystal structure. This is the exact same material and structure as a natural diamond — because it is a diamond.
Moissanite, on the other hand, is silicon carbide with a hexagonal crystal structure. This fundamental difference in chemistry and crystal arrangement is what gives each stone its distinctive properties. A diamond is a diamond; moissanite is a separate gemstone. Comparing them is more like comparing a diamond to a sapphire than comparing two versions of the same stone.
This distinction matters for several practical reasons. Lab-grown diamonds are graded and certified by internationally recognised gemological laboratories (IGI, GIA) using the standard diamond grading system. Moissanite is typically not formally graded in the same way, making quality comparisons less standardised and transparent.
Brilliance, Fire & Light Performance
Both stones are exceptionally brilliant, but they handle light in noticeably different ways. Understanding this difference is key to making a choice you will be happy with for decades.
Lab-Grown Diamond
Refractive Index: 2.42 — Diamonds produce a balanced combination of white light return (brilliance) and colourful spectral flashes (fire), with a dispersion value of 0.044. The result is a sophisticated, elegant sparkle that has defined luxury for centuries.
The light performance of a diamond is what most people picture when they think of a "sparkling" engagement ring. It is bright, lively, and unmistakably classic. The balance between white brilliance and subtle fire is what gives diamonds their timeless, refined look.
Moissanite
Refractive Index: 2.65 — Moissanite has a higher refractive index and significantly more dispersion (0.104 vs 0.044), meaning it produces far more colourful "rainbow" flashes of light. Some people love this intense fire; others find it looks less natural.
In larger stones (above 1 carat), this heightened fire becomes quite prominent and is the most common way that moissanite is visually distinguished from diamond. The effect is sometimes described as a "disco ball" or "rainbow" effect, particularly under direct or artificial lighting.
Hardness & Everyday Durability
For an engagement ring that will be worn every day for a lifetime, durability is not just a nice-to-have — it is essential. Both lab-grown diamonds and moissanite are among the hardest materials used in jewellery, but there is a meaningful difference between them.
Lab-grown diamonds score a perfect 10 on the Mohs hardness scale, making them the hardest known material. Nothing can scratch a diamond except another diamond. This means your lab-grown diamond engagement ring will maintain its pristine polish and sharp facet edges indefinitely, no matter how rough your daily life is on your hands.
Moissanite scores 9.25 on the Mohs scale, which is excellent and places it well above sapphires (9.0), rubies (9.0), and all other common gemstones. For most wearers, moissanite is perfectly durable for daily use. However, the Mohs scale is not linear — the gap between 9.25 and 10 represents a significant real-world difference in scratch resistance. Over years of daily wear, moissanite may develop fine surface abrasion that a diamond would not.
Both stones have excellent toughness (resistance to chipping and breaking) and neither is prone to cracking under normal wear conditions. For a piece of jewellery intended to last a lifetime and beyond, however, diamond's unmatched hardness provides an extra margin of security.
Lab-Grown Diamond vs Moissanite: Full Comparison
A comprehensive side-by-side comparison of every property that matters when choosing between a lab-grown diamond and moissanite for your engagement ring.
Price: What Are You Really Paying For?
Moissanite is significantly cheaper than a lab-grown diamond, and this is often its primary selling point. A 1-carat equivalent moissanite stone typically costs between $300 and $600 CAD, while a comparable 1-carat lab-grown diamond ranges from $1,500 to $3,000 CAD. The price difference is real and substantial.
However, context matters. A lab-grown diamond already costs 50–70% less than a mined natural diamond of the same specifications. So while moissanite is the cheapest option, a lab-grown diamond offers a middle path: genuine diamond at a fraction of the traditional diamond price.
The price you pay for a lab-grown diamond buys you several things that moissanite cannot offer: the prestige and cultural significance of a real diamond, formal IGI/GIA certification and grading, higher resale value, unmatched hardness and longevity, and the classic diamond light performance that has defined engagement rings for generations.
For many couples, the additional investment in a lab-grown diamond over moissanite represents compelling value. You are getting a genuine certified diamond — not a simulant — at a price point that is accessible for most budgets. Browse our ready-made collection to see what a lab-grown diamond ring actually costs.
Resale Value & Long-Term Worth
While neither lab-grown diamonds nor moissanite should be considered financial investments, there is a notable difference in their resale value.
Lab-grown diamonds retain meaningful resale value because they are, fundamentally, real diamonds. They can be sold through second-hand jewellery markets, consignment shops, and online resale platforms. While their resale value is lower than natural mined diamonds, it is substantially higher than moissanite.
Moissanite has very limited resale value. Because it is abundant, inexpensive to produce, and not a rare material, there is little secondary market demand. A moissanite stone purchased for $500 might resell for $50–$100, if at all. The vast majority of moissanite's value is in the setting, not the stone.
If there is any possibility that you might want to upgrade, trade in, or resell your engagement ring in the future, a lab-grown diamond provides meaningfully better value retention.
Which Should You Choose?
Both lab-grown diamonds and moissanite are ethical, beautiful stones that make excellent jewellery. The right choice depends on what you value most:
Choose a lab-grown diamond if: You want a genuine certified diamond. You prefer the classic, balanced sparkle that diamonds are known for. You want the hardest gemstone available for maximum durability. You value formal grading and certification. You want better resale value. You are comfortable investing $1,500–$3,000 per carat (still 50–70% less than a mined diamond).
Choose moissanite if: Budget is your absolute top priority and you want to spend under $600 on the centre stone. You enjoy intense, colourful fire and rainbow sparkle. You are comfortable with a diamond simulant rather than an actual diamond. You do not plan to resell the stone in the future.
At Aurela Diamonds, we believe lab-grown diamonds represent the ideal sweet spot: they deliver the genuine diamond experience — the same chemical composition, the same fire, the same forever durability — at a price point that makes luxury accessible. We would love to help you find the perfect stone for your story.
Frequently Asked Questions
Common questions about choosing between lab-grown diamonds and moissanite.
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