Moissanite vs Diamond vs Cubic Zirconia: Which Stone Is Right for You?
With so many diamond alternatives and simulants on the market, picking the right one isn't always straightforward. Moissanite vs cubic zirconia vs diamond, which one actually deserves your money? And zooming in on cubic zirconia vs diamond specifically, which gives you the better result for your budget?
Here's the short version. Diamond is the hardest and most valuable of the three, made of pure carbon and sitting at a perfect 10 on the Mohs scale. Moissanite (silicon carbide, 9.25 Mohs) is the most brilliant of the group and a widely loved diamond alternative. Cubic zirconia (zirconium dioxide, 8 to 8.5 Mohs) is the most budget-friendly option, though also the least durable.
This guide covers moissanite vs diamond vs cubic zirconia in detail, breaking down what makes each one unique. What you choose ultimately comes down to personal taste, and that choice should feel rewarding, not stressful.
Moissanite vs Diamond vs Cubic Zirconia: Side-by-Side
Here's a full side-by-side comparison across every attribute that actually matters when you're buying. This table alone is worth bookmarking.
|
Feature |
Diamond |
Moissanite |
Cubic Zirconia |
|
Composition |
Pure carbon |
Silicon carbide (SiC) |
Zirconium dioxide (ZrOβ) |
|
Hardness (Mohs) |
10/10 (hardest) |
9.25/10 |
8 to 8.5/10 |
|
Refractive Index |
2.42 |
2.65 to 2.69 (most brilliant) |
2.15 to 2.18 |
|
Dispersion (Fire) |
0.044 |
0.104 (highest fire) |
0.058 to 0.066 |
|
Price per 1ct |
$4,000 to $7,000 natural; $1,000 to $2,000 lab-grown |
$200 to $600 |
$20 to $100 |
|
Durability |
Excellent, lifetime |
Excellent, lifetime |
Moderate, chips and dulls in 2 to 5 years |
|
Color |
Colorless to slightly tinted (D-Z scale) |
Near-colorless, slight tint at certain angles |
Perfectly colorless |
|
Origin |
Naturally mined (rare); lab-grown available |
Lab-created (natural extremely rare) |
Lab-created |
|
Passes Diamond Tester |
Yes (it is a diamond) |
Yes (thermal only) |
No |
|
Eco-Friendly |
Concerns with mined; lab-grown OK |
Yes, lab-grown and conflict-free |
Yes, lab-grown |
|
Resale Value |
Highest |
Some retained value |
Minimal |
|
Best For |
Heirloom and investment pieces |
Daily wear at lower cost with a diamond look |
Fashion jewelry, short-term wear |
The takeaway: if you want a stone that looks like a diamond and lasts a lifetime, moissanite is the strongest value pick. For an heirloom-grade investment, diamond remains unmatched. For affordable fashion jewelry that doesn't need to last forever, cubic zirconia is the easiest entry point.
Audemars Piguet
The History and Origin of Each Stone
Moissanite
In 1893, Nobel Prize winning chemist Dr. Henri Moissan discovered natural moissanite in Arizona, buried in the earth's mantle. Natural moissanite is astonishingly rare, rarer even than diamond, and it only turns up in small quantities within meteorites, kimberlites, and lamproites.
Because natural moissanite is so scarce, scientists set out to recreate it in a lab so more people could enjoy its brilliance. Gem-quality moissanite was first brought to market in the 1990s by Charles Eric Hunter, who founded Charles & Colvard Ltd. The stone was patented in the United States in North Carolina.
Diamond
According to the Gemological Institute of America (GIA), diamonds form deep underground under intense heat and pressure before being pushed toward the earth's surface, where they're eventually found and mined. From there, they go through cleaving, cutting, and polishing before reaching a jewelry setting.
Diamond's popularity dates back to India as early as the 4th century BC, when diamonds were collected from riverbeds. From there, they traveled to Western Europe through trade caravans headed to Venice's medieval markets. By the 1400s, diamonds had become a symbol of European aristocracy. India's diamond supply began to decline in the 1700s, and Brazil stepped in as the dominant source for more than 150 years, discovered by gold miners sifting through river gravel.
Over the following centuries, diamonds became far more accessible as new sources emerged, most notably in Africa. Today, modern technology has made it easier than ever for scientists to locate new diamond deposits.
Cubic Zirconia
Here's something most people don't know: cubic zirconia actually occurs naturally. German mineralogists M. V. Stackelberg and K. Chudoba discovered it in 1937 as microscopic grains within metamict zircon.
Synthetic cubic zirconia was originally developed for lasers and optical equipment. Over time, its production scaled up and eventually overtook older synthetic diamond simulants like strontium titanate, YAG (yttrium aluminum garnet), and GGG (gadolinium gallium garnet).
Today, lab-created cubic zirconia remains hugely popular, set into both fine and fashion jewelry, and available in a wide range of colors that add to its versatility.
For a deeper look specifically at cubic zirconia vs moissanite, check out our blog, Shining The Light On Cubic Zirconia Vs. Moissanite: Which Is The Better Gemstone?
Physical Properties and Characteristics
Moissanite
Moissanite is made of silicon carbide (SiC), with a single carbon atom surrounded by four silicon atoms arranged in a tetrahedral structure.
Refractive index measures how much a ray of light bends as it passes from one medium into another. Moissanite's exceptional fire comes from its high refractive index of 2.65 to 2.69, paired with noticeable double refraction and an adamantine luster.
This is what gives moissanite its signature "disco ball effect," where the stone throws off rainbow color as it moves. That doubling effect is easy to spot under 10x magnification. Moissanite is widely considered the most brilliant gemstone on earth, outshining natural diamond, lab-grown diamond, and cubic zirconia alike.
Moissanite has a specific gravity of 3.22, making it a fairly dense mineral.
Diamond
Diamond is known for three optical traits: fire (its refractive index), scintillation (the sparkle and flashes of light off its facets), and brilliance (the white light it reflects). Diamond has a refractive index of 2.418 and an adamantine luster.
Diamond is made of a single element, carbon, and forms in a cubic crystal system with an octahedral crystal habit. Its specific gravity of 3.52 makes it heavier than moissanite, though still lighter than cubic zirconia.
Cubic Zirconia
Cubic zirconia (CZ) is the cubic crystalline form of zirconium dioxide (ZrO2). It has a refractive index of 2.15 to 2.18 and a specific gravity of 5.6 to 6.0 g/cm3, making it the densest of the three stones.
Durability
Mineral hardness, or resistance to scratching, is measured on the Mohs scale, and it's one of the best ways to gauge how a stone will hold up over time.
Moissanite rates 9.25 out of 10, making it both durable and highly scratch-resistant.
Diamond rates a perfect 10 out of 10, making it the single most scratch-resistant mineral on earth.
Moissanite Watch
Cubic zirconia rates 8 to 8.5 out of 10. It holds up well for regular wear, but it's more prone to abrasion around the facet edges, which can lead to visible chipping over time.
Cost and Value for Money
Moissanite
Moissanite costs significantly less than diamond but more than cubic zirconia. It's a high-quality diamond alternative that can come with a certificate for insurance purposes, and insuring a moissanite ring or pendant is a smart move if you're investing in one. Looking for something one of a kind? Check out our Custom Moissanite Jewelry collection for bespoke designs.
While it doesn't carry the price tag of a natural diamond, moissanite still holds some resale value, and it remains a strong pick for anyone who wants a sustainable, eco-friendly gemstone in place of a mined diamond.
Diamond
Diamond is the most valuable of the three stones and the traditional choice for engagement rings and fine jewelry, widely regarded as the world's most precious gemstone. It's also the least affordable of the three, which makes it more of an investment purchase than an everyday buy.
Its value holds strong over time for buyers who want jewelry that keeps its worth, and pricing depends heavily on the 4Cs: carat weight, cut, clarity, and color. Moissanite is graded using that same 4Cs framework.
Cubic Zirconia
Cubic zirconia costs a fraction of what you'd pay for a diamond or moissanite of the same carat and size, making it the most accessible option for anyone who loves fashion-forward jewelry without the investment-level price tag.
Eco-Friendliness and Ethical Considerations
Moissanite, cubic zirconia, and natural earth-mined diamonds each come with their own environmental and ethical footprint.
Moissanite and cubic zirconia are both lab-created, which means no mining is involved and neither stone is tied to human rights concerns or conflict sourcing.
Diamonds carry more environmental and ethical baggage. Mining impacts the land through soil erosion, deforestation, and water pollution, and the industry has also faced reports of human rights abuses, including forced labor. Conflict-free diamonds exist as a way to address these concerns, though that labeling isn't always independently verified.
Is Moissanite a Diamond?
No, moissanite is not a diamond. It's a completely separate gemstone made of silicon carbide, while diamond is pure carbon. The two look alike to the naked eye since both are colorless, brilliant, and durable, but they're different minerals with different chemical makeups, refractive indexes, and price points.
Part of the confusion comes down to marketing. Plenty of jewelers sell moissanite under the label "moissanite diamond" because it looks like a diamond, passes most thermal diamond testers, and fits into the same engagement-ring settings. Technically speaking, that label isn't accurate. Moissanite is a high-quality diamond alternative, not a diamond itself. Lab-grown diamonds are real diamonds. Moissanite isn't.
If you're trying to figure out whether a stone is moissanite or a genuine diamond, the easiest method is a dual thermal-and-electrical conductivity tester. Moissanite conducts both heat and electricity, while diamond only conducts heat. A dual tester picks up on that difference within seconds.
Is Cubic Zirconia a Diamond?
No, cubic zirconia is not a diamond either. CZ is a synthetic gemstone made of zirconium dioxide, while diamond is pure carbon. It's the most affordable diamond simulant on the market and looks visually similar at a glance, but the two minerals are nothing alike underneath the surface. CZ is softer (8 to 8.5 on the Mohs scale compared to diamond's 10) and has a lower refractive index, so it doesn't sparkle in quite the same way.
To an untrained eye, a CZ stone can pass for a diamond at first look. But side by side and under magnification, the differences show up fast. CZ has almost too-perfect clarity, since real diamonds naturally contain inclusions, along with a slightly different sparkle pattern, and it will fail a standard diamond tester immediately. Think of CZ as costume-grade jewelry: beautiful and accessible, but not designed to last decades the way diamond or moissanite can.
Maintenance and Care
Cleaning your moissanite, diamond, or cubic zirconia jewelry every two to three weeks is a good habit to keep. Regular cleaning clears away bacteria, debris, and buildup from everyday products like lotions and cosmetics.
The warm soapy water method is the simplest way to do it:
- Fill a bowl with lukewarm tap water and mix in a bit of soap to create suds. Marie Claire recommends Dawn dish soap for this.
- Place your ring or jewelry piece in the bowl and let it soak for 10 to 15 minutes so buildup loosens around the stone and setting.
- Gently scrub with a new, soft brush to lift away any remaining dirt. There's no need to use much force here, since excessive pressure can damage delicate design details.
- Rinse thoroughly under cool running water to remove all soap residue, then pat dry with a soft, lint-free cloth or let it air dry.
A couple of extra tips: take your jewelry off before swimming in chlorine or saltwater, and store it in a box, bag, or drawer when you're not wearing it to avoid loss, damage, or unnecessary exposure.
Bust Down Watches
For more detail, check out our in-depth guide, How to Clean Moissanite Ring: 7 Tips to Keep Moissanite Brilliant.
Final Thoughts
So, cz vs moissanite vs diamond, which one is actually right for you?
Cubic zirconia and moissanite are both budget-friendly diamond alternatives that deliver plenty of sparkle and fire without the higher price tag or complex supply chain tied to diamonds.
Moissanite stands out as a high-quality diamond alternative built to last a lifetime. Whether you're shopping for moissanite earrings, rings, or pendants, you're getting a piece designed for long-term wear, not something disposable.
It's a genuinely durable stone, just not quite as durable as diamond. Cubic zirconia sits a step below both, more prone to abrasion and chipping over time.
Diamond will always hold its place as the most prestigious and sought-after gemstone, synonymous with luxury. That doesn't make the alternatives any less worthwhile. Moissanite and cubic zirconia both offer the same look, in the size you want, at a fraction of the cost.
Frequently Asked Questions
Which is better: moissanite, diamond, or cubic zirconia? It really depends on your budget and how long you need the stone to last. Diamond is the right choice if you want an heirloom-grade stone that holds its value across generations, since it's the hardest and most expensive of the three. Moissanite suits buyers who want a diamond-like look at roughly 10 percent of the cost while still getting a lifetime-durable stone. Cubic zirconia works best for fashion jewelry where cost matters more than long-term wear.
How much cheaper is moissanite than diamond? Moissanite typically runs 80 to 90 percent less than a natural diamond of the same size and quality. A 1-carat moissanite usually costs $200 to $600, while a 1-carat natural diamond can run $4,000 to $7,000 or more. Lab-grown diamonds land in between, usually $1,000 to $2,000 for a 1-carat stone.
How much cheaper is cubic zirconia than diamond? Cubic zirconia typically costs about 99 percent less than a natural diamond. A 1-carat cubic zirconia usually runs $20 to $100, compared to $4,000 to $7,000 or more for a 1-carat natural diamond. That massive price gap reflects the fact that CZ is mass-produced and not built to last for decades.
Will moissanite or cubic zirconia pass a diamond tester? Moissanite passes a standard thermal diamond tester because it conducts heat at nearly the same rate as a real diamond. Cubic zirconia does not pass a thermal diamond tester. It fails immediately, since zirconium dioxide has very different thermal properties from diamond.
Can a jeweler tell the difference between moissanite, diamond, and cubic zirconia? Yes, every time. A trained jeweler can identify all three within seconds using a 10x loupe. Moissanite shows double refraction, meaning facet edges appear to double, along with an unusually rainbow-colored fire. Diamond shows single refraction and an icy-white sparkle. Cubic zirconia has almost too-perfect clarity, since real diamonds contain natural inclusions, along with a slightly softer luster.
Is moissanite a "fake" diamond? No. Moissanite isn't fake anything. It's a distinct, genuine gemstone with its own chemistry, name, and value. It's sometimes marketed as a "diamond simulant" or "diamond alternative" simply because it visually resembles diamond, but that's a description of its market position, not what it actually is. Moissanite has been a recognized gemstone since its discovery in 1893 by Nobel laureate Henri Moissan, and it's graded on the same 4Cs scale used for diamonds.
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