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Cubic zirconia vs diamond

Cubic zirconia

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Learn about the differences between cubic zirconia vs diamond, and discover the allure and characteristics of these stunning gemstones as we explore their unique properties.

What is cubic zirconia?

Cubic zirconia is classified as a diamond simulant, which is a stone that looks similar to a diamond but is made of a different material. Composed of zirconium oxide (ZrO2) with a cubic crystal structure, cubic zirconia captivates with its visual similarities to its pricier counterpart and is a great alternative to be used in a wide range of fashion jewellery, from elegant earrings to dazzling necklaces and bracelets.

How are cubic zirconias made?

Cubic zirconia (CZ) is a synthetic gemstone that is carefully crafted in laboratories.

First, zirconium oxide and yttrium oxide are combined and exposed to intense heat, forming the basis for CZ production. Then, controlled cooling allows cubic crystals to grow, contributing to the gemstone's unique structure. 

Skilled technicians then shape the CZ material into rough pieces using diamond-cutting tools and techniques. To enhance the gemstone's appeal and optical properties, the rough pieces undergo a meticulous polishing process, which involves grinding and buffing to create a smooth, lustrous surface that showcases its inherent brilliance and transforms them into lustrous gemstones.

This affordable alternative to diamonds offers remarkable brilliance and elegance, although it should be noted that CZ lacks the same hardness as diamonds.

Diamond vs cubic zirconia

When it comes to comparing the allure of diamonds and cubic zirconias, several factors set them apart. Let's explore the key distinctions:


While both cubic zirconias and diamonds can be colourless but exhibit a broad spectrum of colours, it's important to note that the colouration in cubic zirconia is intentionally added during manufacturing, whereas the colour in diamonds can occur naturally. The ability to create a desired colour range makes cubic zirconia more versatile in terms of aesthetic options, while mined diamonds possess a unique beauty in their natural colour variations.


As an artificial gemstone, cubic zirconias lack flaws and so have excellent clarity. Diamonds, on the other hand, have naturally occurring inclusions, which is what makes each one of them unique. Flawless diamonds are incredibly rare.


When examining both stones under natural light, diamonds show exceptional brilliance and fire, while cubic zirconia shows a noticeable rainbow of a more synthetic-coloured light.


While cubic zirconia is relatively durable with a Mohs hardness score of 8 to 8.5, it falls short of the extraordinary hardness of diamonds, which score a perfect 10. Extra care should be taken to avoid scratches and abrasions.


Perhaps one of the most appealing aspects of cubic zirconia is its affordability compared to mined diamonds. As a more budget-friendly alternative, cubic zirconia offers an opportunity to enjoy a diamond-like aesthetic without the higher price tag. 

Are there any other good diamond alternatives?

Other than cubic zirconias, the other widely available diamond simulant is moissanite. So, if you have a colourless stone, and you’re not sure whether it is a real diamond or not, you might want to read our article How To Tell If A Diamond Is Fake.

However, lab grown diamonds are a better alternative than either cubic zirconia or moissanite. They are real diamonds with identical physical and chemical properties as mined diamonds, and they exude the same captivating beauty and sparkle as their mined counterparts. Lab grown diamonds are ethically and sustainably produced, reducing the environmental impact of diamond mining. These affordable gems offer a compelling choice for those seeking high-quality, conflict-free diamonds. Read more about them in our Guide to Lab Grown Diamonds.


Is cubic zirconia a good diamond alternative?

Considering cubic zirconia as a diamond alternative relies on your preferences, budget, and expectations. For an affordable, visually appealing option resembling diamonds, cubic zirconia can be suitable, however, there are currently other affordable options, such as lab grown diamonds, that have the unique properties and longevity of mined diamonds.

Does cubic zirconia have good resale value?

No, cubic zirconia lacks significant resale value compared to mined diamonds or precious gemstones. Being a man-made synthetic gemstone with a lower perceived worth, cubic zirconias are less desirable in the resale market. Its susceptibility to wear, scratches, and diminished brilliance can further impact its value, and compared to diamonds, there’s lower demand for second-hand CZ jewellery. Additionally, advancements in technology, like lab-grown diamonds, have influenced CZ's resale value.

Are cubic zirconia the same as lab-grown diamonds?

No, cubic zirconia (CZ) and lab-grown diamonds are not the same. They are made of different materials with distinct compositions and properties.
While both cubic zirconia and lab-grown diamonds are created in a laboratory setting, the main distinction lies in their composition and properties. Lab-grown diamonds are real diamonds, while cubic zirconia is a synthetic material used as a diamond simulant.


Cubic zirconias and diamonds are both popular gemstones that are used in jewellery, but upon closer scrutiny, they are vastly different in terms of their properties, value, and durability. 

Cubic Zirconia (CZ), a synthetic gemstone formed in laboratories using zirconium oxide, is renowned for its affordability, versatility, and durability. It often serves as a more budget-friendly alternative to diamonds, with the ability to be cut and polished to imitate their radiant allure. On the other hand, mined diamonds are naturally occurring mineral crystals that are formed deep within the Earth. All diamonds, whether mined or lab grown are composed of pure carbon and are the hardest occurring substance on Earth, making them an ideal choice for jewellery.

While both gemstones may look similar, diamonds are much more durable and valuable than CZ, making them the preferred choice for those looking for a high-quality, long-lasting piece of jewellery.

If you have any questions, please feel free to get in touch and we'd be happy to help.

David Rhode
Together with Tim Ingle, David created Ingle & Rhode to offer a better alternative to the traditional luxury brands. Since 2007, we’ve provided our customers with genuinely ethical engagement rings, wedding rings and fine jewellery – free from conflict diamonds, dirty gold and child labour. With more than 16 years experience in the jewellery industry, David has deep expertise in diamonds, gemstones and jewellery design and manufacturing.