Are Moissanite and Lab-Grown Diamonds the Same? A Complete Comparison

Is Moissanite a Lab-Grown Diamond?

I’ve spent weeks researching this topic after my sister asked me whether Moissanite was “just a fake lab diamond.” Turns out, the jewelry world is filled with misconceptions, and this is a big one.

Moissanite and lab-grown diamonds look similar at first glance, but they’re entirely different gemstones. I was surprised too when I first learned this.

The straight answer? No, moissanite is not a lab-grown diamond. It’s like comparing apples to pears – both fruit, both delicious, but fundamentally different.

What makes them different? Chemistry, for starters. Moissanite is made of silicon carbide, while lab diamonds are pure carbon. This seemingly small distinction creates massive differences in how they sparkle, what they cost, and how they perform as jewelry.

I’ve noticed that people shopping for engagement rings or special occasion jewelry often stumble upon both options when looking for alternatives to mined diamonds. Each stone has its champions and critics.

Having examined both stones up close (and even wearing moissanite myself for a while), I’m sharing what I’ve discovered about these fascinating gemstones. Let’s break down the real differences between moissanite and lab-grown diamonds so you can figure out which one might be right for you.

What Is Moissanite?

Moissanite has an almost magical origin story. It was first discovered in a meteor crater! How cool is that? French scientist Henri Moissan found tiny particles of this crystal in 1893 while digging through meteorite fragments in Arizona. Natural moissanite is incredibly rare on Earth – you’re not going to stumble across it on a hike.

The jeweler at my local mall explained that virtually all moissanite in jewelry comes from labs today, which makes sense given how scarce the natural material is. I noticed this trend extends beyond traditional rings – even mens moissanite chains have gained popularity as more people discover this brilliant alternative gemstone for various jewelry pieces.

The Origin of Moissanite

The moissanite you’ll find in jewelry stores isn’t from outer space, unfortunately. Scientists have developed methods to create silicon carbide crystals in controlled laboratory environments. The chemistry is completely different from diamonds – moissanite’s formula is SiC rather than carbon alone.

I remember reading that commercial moissanite production only really took off in the 1990s. Before that, creating these gems in sizes large enough for jewelry seemed nearly impossible. The breakthrough came when researchers figured out how to grow silicon carbide crystals that could rival diamonds in beauty.

My friend who works at a jewelry store told me that many customers come in thinking moissanite is just another type of lab diamond, but she always explains that they’re completely different materials with different properties.

Physical Properties of Moissanite

What impressed me most when researching moissanite was its incredible hardness. It scores 9.25 on the Mohs scale, making it tougher than nearly everything except diamonds. I’ve worn my moissanite ring everyday for three years, including through gardening and home renovations, and it still looks brand new.

The thing that really sets moissanite apart is its crazy high refractive index – between 2.65 and 2.69 compared to a diamond’s 2.42. In normal-person terms? It’s flashier. Way flashier. When I walk from indoor lighting to sunlight, my moissanite ring practically explodes with rainbow colors.

Visual Characteristics of Moissanite

The first time I saw moissanite and diamond side by side, the difference was obvious – moissanite throws off way more colorful reflections. Some people call this extra “fire” or “disco ball effect.”

My mom thinks my moissanite ring is too sparkly, while my best friend absolutely loves the rainbow flashes. It’s definitely a matter of personal taste.

Modern moissanite looks pretty much colorless in most lighting. I’ve noticed my stone occasionally shows a slight greenish tint under certain fluorescent lights, but it’s barely noticeable. The jeweler mentioned that older moissanite sometimes had more noticeable color tints, especially in larger stones, but the newer ones are much clearer.

Moissanite Varieties

When shopping around, I came across several moissanite brands, each with slightly different marketing claims:

Charles & Colvard seems to be the OG moissanite company. Their Forever One stones were consistently recommended on the forums I browsed. They look super white and clear, with grades similar to the D-E-F range in diamonds.

I also checked out brands like Harro Gem and MoissaniteCo. The differences between brands aren’t huge, but each has slight variations in cut style and production methods. After trying to spot differences in person, I can say they’re all pretty impressive.

A jewelry designer friend mentioned that she sources from Tianyu Gems sometimes, which apparently offers great quality for slightly lower prices.

What Are Lab-Grown Diamonds?

I visited a local jeweler who specializes in lab diamonds last summer, and what fascinated me was that lab-grown diamonds aren’t imitations – they’re actual, real diamonds with the identical carbon structure as mined ones. The only difference is they’re grown in machines instead of in the earth over millions of years.

The jeweler let me examine some lab diamonds under a loupe, and honestly, I couldn’t tell them apart from the mined diamonds in another case. Same sparkle, same optical properties.

How Lab Diamonds Are Made

From what I understand, there are two main ways to create lab diamonds, and they sound like something out of a sci-fi movie:

The HPHT method (High Pressure High Temperature) essentially recreates the intense conditions deep in the earth’s mantle where natural diamonds form. When the jeweler explained the massive presses and extreme heat involved, I pictured some kind of mad scientist lab. Apparently, this older method sometimes produces diamonds with slight color tints.

Then there’s the CVD method (Chemical Vapor Deposition) which somehow “grows” diamonds layer by layer in a chamber filled with carbon gas. I watched a YouTube video showing this process and it’s mesmerizing – you literally see a diamond crystal getting bigger over time as carbon atoms stack up.

Either way, the result is chemically identical to a mined diamond. This still blows my mind.

Physical Properties of Lab Diamonds

Lab diamonds score a perfect 10 on the Mohs hardness scale – nothing natural or man-made is harder. My cousin has had a lab diamond engagement ring for five years of heavy wear, and it looks precisely as it did the day she got it.

What’s interesting is that lab diamonds have the exact same refractive index (2.42) as natural diamonds. This gives them that characteristic diamond sparkle that’s more white-bright than rainbow-colorful. When my friend and I compared her lab diamond to my moissanite under the same lighting, the difference in how they handled light was immediately obvious.

Lab Diamond Quality Factors

The jeweler I spoke with explained that lab diamonds are graded using the exact same 4Cs as mined diamonds:

Cut affects that beautiful light performance we all want. My friend’s lab diamond has an excellent cut that makes it sparkle like crazy, even in dim restaurant lighting.

Color grades work the same way too. Lab diamonds range from completely colorless (D) to those with slight yellow or brown tints. Most people seem to go for the G-H range, which looks perfectly white to the naked eye but costs less than the D-F range.

For clarity, lab diamonds often have fewer inclusions than natural ones. The jeweler showed me some under magnification, and explained that while lab diamonds can have inclusions, they tend to be different types than those in natural diamonds.

Carat weight is straightforward – bigger diamonds cost exponentially more, whether lab-grown or mined. Going from a 1-carat to a 2-carat lab diamond more than doubles the price.

Key Differences Between Moissanite and Lab Diamonds

After handling both stones extensively and talking to people who own each, I’ve found several key differences that go beyond just price. These distinctions helped me understand why some people strongly prefer one over the other.

Chemical Composition

The fundamental difference lies in what these stones are made of. Moissanite is silicon carbide, while lab diamonds are pure carbon arranged in a crystal structure.

I remember my high school chemistry teacher explaining that molecular structure determines everything about a material’s properties. This holds true here – the silicon in moissanite creates different optical effects and physical properties than the pure carbon structure of diamonds.

When I asked a gemologist why this matters, she explained that composition affects everything from how light interacts with the stone to how it might wear over decades.

Brilliance and Fire

The most obvious difference when you see these stones side by side is how they handle light. Moissanite has significantly more “fire” (those colorful flashes) than any diamond, lab-grown or natural.

My moissanite ring practically throws rainbows on my wall when sunlight hits it. My sister’s lab diamond, by contrast, has more white brilliance – like pure, bright flashes rather than colorful ones.

This difference becomes even more noticeable in larger stones. I tried on a 2-carat moissanite that was almost too flashy for my taste, while a 2-carat lab diamond had a more subdued, classic sparkle.

Hardness and Durability

Both stones are incredibly durable, but lab diamonds edge out moissanite slightly in hardness (10 versus 9.25 on the Mohs scale).

In real-world terms, I haven’t noticed any practical difference. Both resist scratching amazingly well. My jeweler friend mentioned she’s never had a customer come back with a damaged moissanite or lab diamond from normal wear.

I did manage to put a tiny scratch on my metal setting long before the moissanite showed any wear at all. Both stones should last essentially forever with basic care.

Color Characteristics

Something I noticed while trying on different stones was how moissanite sometimes shifts color slightly in different lighting. Under department store fluorescent lights, my moissanite sometimes shows a subtle greenish tint that disappears completely in natural light.

Lab diamonds maintain their color consistently across different lighting conditions. My friend’s F-color lab diamond looks identically colorless whether we’re in her kitchen, at a restaurant, or outside.

I’ve read that newer moissanite production has minimized this color shift, but it’s still something to be aware of, especially in stones larger than 1 carat.

Conclusion: Making Your Choice

After months of research and personally testing both options, I can definitively answer the question “is moissanite a lab grown diamond?” with a clear no. They’re entirely different gemstones with their own unique properties. Moissanite is made of silicon carbide, while lab diamonds are carbon-based just like mined diamonds.

For my personal choice, I went with moissanite because I loved the extra sparkle and the dramatically lower price point. My sister chose a lab diamond because she wanted a genuine diamond with the classic sparkle she’d always envisioned.

My best advice? Try to see both stones in person if possible. Read opinions online, but nothing beats actually seeing these gems with your own eyes. The differences in sparkle and fire appear more or less significant to different people.

Are Moissanite and Lab-Grown Diamonds the Same? A Complete Comparison was last updated March 4th, 2025 by Hambrick Guthrie