Moissanite vs Cubic Zirconia: The Cost, Properly Compared

The question behind the question

Most people arriving at this comparison already know the materials differ. What they want is a number: how much more is moissanite, and is the difference worth it. The honest answer has three parts, and only the first is the one people expect.

1. Per carat, moissanite costs several times what CZ costs. That is true and it is consistent across sellers.
2. Per finished piece of jewelry, that gap frequently disappears, because at this tier the metal and the setting labor cost more than either stone.
3. Over ten years, moissanite is usually the cheaper of the two, because CZ in a daily-wear piece is a consumable.

This page is about those three numbers. If what you want is the material comparison - what each stone is, how they look, how they test - that is cubic zirconia vs moissanite, and it is worth reading first.

Why the two stones cost what they cost

The price difference is a manufacturing difference, not a rarity difference. Neither stone is rare - both are made industrially in quantity.

Cubic zirconia is zirconium dioxide, stabilised with yttrium or calcium and grown by skull melting: the material is melted in a crucible formed from its own cooled crust, then allowed to crystallise as it cools. It is a fast, high-yield, cheap process. CZ has been produced at commercial scale since the 1970s and the price per carat of rough is trivial - which is why a CZ stud set costs less than lunch.

Moissanite is silicon carbide. Growing gem-quality colorless SiC is slow, energy-intensive and lower-yield: crystals are grown over days rather than hours, and the colorless grades that work in jewelry are a fraction of the output. Silicon carbide is also extremely hard to cut, which adds real cost at the lapidary stage rather than just at the growth stage. Those two facts - slow growth and difficult cutting - are the entire price premium.

What the extra money actually buys

The row that decides the purchase is the clouding one. CZ does not degrade chemically, but at Mohs 8 to 8.5 it is soft enough that daily contact with household grit - which is largely quartz at Mohs 7, plus harder particles - puts microscopic abrasion across the facets and especially the facet edges. The stone stops returning light crisply and reads as cloudy or glassy. It cannot be polished back at home, and on a $15 stud it is not economic to have it done professionally.

Moissanite at 9.25 is above almost everything it meets in ordinary life. A moissanite stud worn daily for a decade looks the same as it did on day one. That is the whole of what the premium buys - not better looks on day one, where moissanite's higher dispersion actually makes it more fiery than diamond and some people prefer the quieter CZ, but the same looks on day three thousand. Each stone measured against diamond itself is covered in moissanite vs lab diamond and cubic zirconia vs diamond.

The number most comparisons miss: the setting

Here is the part that changes the decision, and it is visible in the live prices in the table at the top of this page. The CZ tennis necklace listed above costs more than the 2.0ct moissanite studs. Not because CZ is expensive - it is not - but because a tennis necklace is dozens of individual settings, each one hand-set, on a continuous length of sterling silver. The stones are a rounding error in that bill.

That generalises. At the price tier this site covers, the cost of a finished piece breaks down roughly as:

• The metal - sterling silver by weight, or a plating over it. Silver is benchmarked by weight on an open market, so this is a hard floor; sterling silver price explained shows how that floor is calculated.
• The setting labor - one solitaire is cheap; thirty channel-set stones are not.
• The stone - which for CZ is nearly free, and for moissanite is real but is rarely the largest line.

The practical consequence: on a simple piece with one stone, moissanite costs noticeably more than CZ. On a complex piece with many small stones, the choice of stone barely moves the price, so there is no reason not to take the harder one - and conversely, no reason to pay a large premium for a multi-stone moissanite piece whose cost is in the labor either way.

Doing the arithmetic on a listing yourself

Both stones are sold with a stated carat weight, so the per-carat comparison is arithmetic you can do at the point of purchase. It takes about fifteen seconds and it is the single most useful habit in this category:

1. Find the total carat weight, not the per-stone weight. A “2ct” stud listing is almost always 1ct per ear. Listings mix the two deliberately.
2. Divide the live price by the total carats. That is your cost per carat, including the setting.
3. Do the same for a plain solitaire in the same metal. The gap between the two is roughly what the setting complexity is costing you.
4. Divide by the years you expect to wear it. For CZ in daily wear, use two. For moissanite, use as many as you like.

That last step is where the comparison usually flips. A CZ piece replaced three times over a decade costs more in total than one moissanite piece bought once - and you spent the decade wearing something that looked tired for the second half of each cycle.

Beware the carat-weight vocabulary

One technical trap worth knowing, because it makes cost-per-carat comparisons misleading if you miss it. Carat is a unit of weight, not size, and these three materials have different densities. Moissanite is less dense than diamond and CZ is more dense than diamond. So a “1 carat” moissanite is physically larger than a 1 carat diamond, and a 1 carat CZ is physically smaller.

Sellers handle this by quoting “diamond equivalent weight” or “DEW” - the weight a diamond of that physical size would have. It is a sensible convention, but it means a moissanite listed as 1ct DEW weighs less than one carat, and comparing a DEW figure to a true carat figure overstates the moissanite's price per carat. If you are comparing two listings, check that both are quoting the same thing, and when in doubt compare millimeter diameters instead - those are unambiguous.

The honest recommendation, by what you are buying

• Daily-wear studs or a daily ring: moissanite. It is cheaper over a decade and it does not go cloudy.
• Occasional or event jewelry: CZ. It will not accumulate the wear that makes hardness matter, and the money saved is real.
• A multi-stone piece - tennis bracelet, tennis necklace, eternity band: buy on the metal and the setting quality, because the stone choice barely moves the price.
• A ring that will take knocks: moissanite, and check the setting height. A soft stone in an exposed setting is the fastest way to a chipped stone.
• A white stone that is neither of these: lab-created white sapphire is a third option with its own cost structure - cubic zirconia vs white sapphire compares them.
• Something intended to be an heirloom: neither - a lab-grown diamond is a real diamond at a fraction of the mined price, and lab grown diamond prices does that arithmetic.

What neither stone is

Both are sold honestly on this site and should be sold honestly everywhere: moissanite is silicon carbide and cubic zirconia is zirconium dioxide. Neither is a diamond, neither is a “lab diamond,” and the FTC rules on when the word diamond may be used are specific about this. Moissanite listings using diamond grading language - D color, VVS1 - are applying a diamond vocabulary to a different mineral; it is a seller's description rather than a recognised grading of that species, and it should be read as a rough quality indication rather than a certified grade.

The GRA reports that ship with inexpensive moissanite are produced by the seller's own supply chain rather than by an independent laboratory of record. They are not worth paying extra for and they are not evidence of anything in particular - diamond alternatives compared goes through what each certificate in this category actually is.