Moissanite vs Cubic Zirconia: Best Diamond Alternative Choices

moissanite and cubic zirconia rings

Despite having several choices, shoppers still choose diamonds over all other white or clear gemstones. They continue to be the most popular choice for engagement rings. These revered stones look lovely against all skin tones and metal settings. 

However, shoppers have found that moissanite and cubic zirconia offer an affordable alternative. These beautiful stones suit most budgets. 

Alternatives for Mined Diamonds

Mined diamonds have been the most popular option for decades. The political and ecological ramifications of mining for diamonds make alternatives an attractive option for consumers. 


Moissanite is not a diamond but looks just like one. It is a diamond simulant that does appear in nature, but rarely. Gemologists make most moissanite gemstones in labs from natural silicon carbide.

Cubic Zirconia

Like moissanite, cubic zirconia comes from labs. Cubic zirconia, or CZ, is not a diamond. It is also a diamond simulant made of a crystalline material called zirconium dioxide. Unlike moissanite, miners cannot find the stone in nature. 

Moissanite vs Cubic Zirconia: Side-by-Side Comparison

Two clear, faceted stones side-by-side and isolated on a white background

Moissanite and cubic zirconia are not the same as real diamonds. Although, to the naked eye, their optical qualities make it difficult to tell the three gemstones apart. 

History and Origin

Henri Moissan first discovered the eponymous stone moissanite in a meteor crater in the 1890s. Because the stone most likely comes from outer space, some people call it a space diamond or stardust diamond. 

Researchers first discovered cubic zirconia in the 1930s. The stone includes a compound of zirconium and oxygen, and moissanite is a combination of silicon and carbon. Since diamonds are a carbon-based mineral, moissanite and diamonds have more similarities than CZs and diamonds. 

The space-related romantic history and diamond-like appearance drives more consumers toward moissanite, even if their stones come from a lab. 


One quality people love about diamonds is their brilliance or light performance—how the light bends as it moves through the stone. Diamonds have a refractive index of 2.42, while moissanite has a refractive index of 2.65. The higher the refractive index, the more brilliance a gem has. 

Cubic zirconia has a refractive index of 2.15, giving them plenty of brilliance under lights, but not to the same degree as diamonds and moissanite. Unfortunately, the minimal sparkle makes CZs look glassy. It’s especially noticeable if they’re sitting next to brilliant diamonds and moissanite. 

Consumers are drawn to moissanite because the high refractive index gives the stone more sparkle and fire. 

Color and Clarity

Gemologists rate white stones on a color chart that moves from D to Z. Gemstones with a D rating are colorless. Diamonds with a D rating are rare and incredibly expensive. Almost all cubic zirconia have a D color rating. Moissanite is rarely colorless or transparent. The stones usually have a tint of green, gray, or yellow - just like diamonds. 

Because of the D rating, CZs can look unnatural. Still, many consumers like the colorless appearance. 

Colored diamonds have become popular in recent years. Moissanite and cubic zirconia also come in several popular colors but at a fraction of the price of colored diamonds. Both stones come in blue, purple, pink, brown, amber, and champagne. 

Cost and Value

Close-up of moissanite in jewelers tweezers

Moissanite and cubic zirconia are affordable options for people who do not want to spend thousands on natural diamonds. Moissanite’s price per carat varies, while the average price per carat of a CZ is about $20. 

Moissanite has a better resale value than cubic zirconia because of the romanticized history and the natural value of the stone. Overall, moissanite is about 90% less expensive than the typical diamond. 


Diamonds are the easiest stone to maintain because of their hardness and durability. Both moissanite and cubic zirconia need regular cleanings because they can become cloudy and hazy. You can clean both with soap and water or with a gentle jewelry cleaner. 

Moissanite and cubic zirconia do not have the same oily quality as diamonds, so they become dirty faster. If your stones look hazy, they just need cleaning. Both stones need routine cleaning to keep them sparkly and full of fire. 


Gemstone hardness is measured on the Mohs scale. Diamonds have a score of 10 because they are the hardest natural gemstone on the planet. Moissanite has a Mohs score of 9.25, while CZs have a hardness rating of 8 to 8.5. 

Because both are hard stones, they are unlikely to chip. However, if you wear a large CZ ring, there is a chance it could chip. They are better used in earrings and pendants. Moissanite is a good choice for all types of jewelry because it is highly unlikely to chip. 

Moissanites have a PSI rating of 7.6, showing they are durable under extreme pressure. On the flip side, CZs have a PSI rating of 2.4. Comparing the hardness of the two gems, CZ is less than half as durable as moissanite. 

Hardness also measures how likely a stone is to scratch or break down under chemical or temperature changes. Because CZs have a lower rating, they have less resistance to these extremes. 

Comparing moissanite to CZs, moissanite is 219% harder and over 300% more resistant to chipping. 

Moissanite and Cubic Zirconia Shopping Guide

A woman choosing between several moissanite and cubic zirocnia rings

When buying precious or semi-precious stones, be mindful of scams. Consider these tips when shopping for moissanite and cubic zirconia: 

Buy From a Trusted Source

Scammers might advertise moissanite and cubic zirconia, but they might not sell the actual gemstones. It is easy to replace stones with cut glass, and unsuspecting consumers may get duped.

Read Reviews and Feedback

If you are buying online, read the reviews from actual buyers. Only buy from retailers who have reviews from verified buyers, especially if you are purchasing on Amazon. 

Ask for Return Policies in Writing

Another way to guarantee you have a real stone is to ask about return policies. Online retailers should accept returns for a reasonable time. You should be able to take the stone to a local jeweler to see if it is a genuine moissanite or cubic zirconia. Then, return the stone if it does not meet your expectations. 

Check Videos and Photos of the Actual Stone to See Its Brilliance

Before buying a stone online, ask the retailer to send you a video of it. Watch the light performance. Ask the jeweler to show you where any flaws might be. You can also ask to see it side-by-side with other stones to assess the color rating. 

Only Buy From a Reputable Seller or Shop

If you are concerned about buying from an online retailer, you can purchase your stone from a local jeweler. Choose a retailer with a solid reputation for selling genuine stones and giving guarantees. 

Summing It Up

Close-up of a hand displaying a set of diamond jewelry

Moissanite and cubic zirconia can be safe and affordable jewelry investments. As with all gemstones and jewelry, you should be cautious when shopping. Scammers are continually trying to pass cut glass as authentic diamonds and simulants. 

To the untrained, naked eye, moissanite, cubic zirconia, diamonds, and cut glass look similar, especially when cut to less than one carat. 

When shopping, opt for moissanite if you are looking for a large gemstone on a ring setting. Moissanite is harder and more durable than cubic zirconia, so it is less likely to chip and crack when in a ring setting. 

Choose cubic zirconia if you are shopping for earrings or a pendant, as this type of jewelry is less likely to be damaged. People are less likely to get a close-up look at earrings or pendants. They are less likely to recognize that they aren’t genuine diamonds or moissanite. 

Cubic zirconia makes good choices for earrings simply because they all have the same color grade. Because of their D color grade, they all match perfectly. 

When choosing a stone, consider the high hardness and toughness of moissanite. It will not scratch, chip, or wear like CZs. The refractive index also makes them a top choice for consumers who want to show off their brilliant engagement rings.  

Moissanite and cubic zirconia both have beautiful brilliance and exceptional value. They are great choices for people who want clear gemstones but don’t want to pay thousands of dollars for them.