Cubic Zirconia vs Gemstones: Which is best?

gemstones for jewellery

The gemstone, cubic zirconia, is robust and generally colourless, though colour can be added. In jewellery, it is widely used as a simulant for different gemstones, meaning that it is used to replace naturally occurring gemstones, especially diamond simulants.

People are often confused by diamond, zircon and cubic zirconia because of their physical similarities. However, each has a very different chemical and molecular makeup up. And, if you know what to look for, you can easily see the difference between the three.

So, what is cubic zirconia? Cubic zirconia is a widely used diamond simulant. Used amongst jewellery manufacturers since the 1970s, it is lab-created ZNO2 (crystalline zirconium dioxide). The crystal gem is transparent and colourless, bearing diamond-like visual properties and measuring 8.5 on the Mohs' hardness scale.

While diamonds and Zirconia are certainly a rarer form of gemstone and largely more sort after for engagement rings and other rings, cubic zirconia crystals are still excellent in jewellery design.

The Pros of Cubic Zirconia

Elegant Necklace - 925 Sterling Silver Jewellery Heart Pendant Dephini

We love the cubic zirconia as an affordable diamond simulant. Here are just a few of the reasons we do:

  • Affordable diamond simulant;
  • CZs are now available in almost every colour imaginable (trace mineral impurities add colour);
  • The metal oxide film is available for iridescent effect-also known as the "mystic" finish;
  • CZs are nearly always flawless;
  • Aids in light refraction, making them seem brighter and with more sparkle;
  • Cubic zirconia can be cut into a range of bead and gem shapes;
  • Easy to clean & maintain with a polishing cloth. 

Cubic Zirconia vs Diamond

Gemstones, including cubic zirconia (CZ) and diamonds, are diverse in quality, beauty and value. There are instances of a diamond Cubic Zirconia switch, where the diamond may have been switched with cubic zirconia. While the two are similar, they differ in physical value and slight variations in appearance.

A common misconception is that cubic zirconia is a synthetic, lab-grown, lab-treated diamond. In reality, lab-grown diamonds are chemically the same as naturally occurring diamonds. A synthetic diamond is chemically and visually identical to a naturally occurring diamond. Therefore, synthetic diamonds are much more expensive than cubic zirconia.

Cubic zirconia is not a diamond. Instead, it is a diamond simulant that looks similar but not exactly like a diamond.

Cubic Zirconia is more often used in pendants, bracelets and necklace designs and is synthesised in a laboratory. Cubic zirconia gemstones can also turn cloudy. The difference in hardness between the pair is only slightly noticed. A gemstones refractive index in its natural form can give its fire and will flash and reflects more light than a diamond will.

Cubic Zirconia vs Diamond: Value

  • Diamond is marketable
  • Cubic zirconia adage is non-marketable 

A diamonds price is determined by several factors, including size, cut, clarity and colour grade. For example, one-carat well-cut, high-quality diamond varies from $1,800 USD to more than $18,000 USD. In comparison, a two-carat diamond with lower grade cut, shape, clarity, and colour could cost as little as $6,000 US up to $60,000 USD.

In comparison, one-carat cubic zirconia is roughly valued at $20 USD. As such, the crystals are more affordable for people's budgets, especially in pendant and necklace designs.

Cubic Zirconia vs Diamond: Durability and Density

  • Diamond Mohs Scale 10
  • Cubic zirconia Mohs Scale 8 - 8.5

Cubic zirconia is softer than a diamond with an 8 - 8.5 Mohs Scale than the 10 Mohs Scale. As a diamond is harder, it is considered more durable. However, cubic zirconia is an excellent simulant and is also considered a durable stone in its own right.

The difference between the stones can be distinguished easily by having one weigh the stones. A one-carat diamond ring appears to be slightly bigger than a one-carat CZ crystal. It is slightly denser than a diamond and can cut glass or scratch is similar to a diamond.

One property that differentiates CZ from a natural diamond is its thermal conductivity. Lab-created cubic zirconia is a thermal insulator, whereas diamond is a thermal conductor.

Cubic Zirconia vs Diamond: Clarity and Color

Cubic zirconia is artificial and thus lacks the natural imperfections as a diamond. CZ crystals always have excellent clarity and brilliant shine and are nearly always flawless. The flawless nature of cubic zirconia is a tell-tale sign that it is a man-made gemstone. 

A perfect diamond is remarkably rare and expensive. The natural process of diamond formation offers rarity, brilliance, and exclusivity between diamonds, inspiring the search for more rare diamond types.

Cubic zirconia is typically colourless or transparent, though, through modern technology, CZs are now available in almost every colour imaginable, including orange, red, blue, green, orange and yellow. Trace elements are added to the crystal for colouring:

  • Yellow, orange and red are made with cerium
  • Green is made with chromium
  • Golden brown stones are created with titanium

Cubic Zirconia vs Diamond: Beauty and Brilliance

  • Diamond Refractive Index = 2.417
  • Cubic zirconia Refractive Index = 2.150 - 2.182

In contrast, the light passes in cubic zirconia significantly differently, leaving substantially less reflecting on the eyes. The CZ crystal stone shows a more significant dispersion density between 0.058 and 0.066 than 0.044 of diamonds.

Overall, cubic zirconia doesn't rival the beauty of diamonds, but they are the best simulant on the market. A 0.8-carat diamond ring will radiate more brilliance than any cubic zircon of any size. However, to a large majority of people, no one would know the difference.

Zircon Vs Cubic Zirconia


Zircon and cubic zircon are two highly different gemstones. In both their colourless forms, cubic zirconia is made of zirconium oxide, whereas Zircon is made of zirconium silicate. It can be hard to differentiate between diamonds because they all nearly look the same look as a diamond. But that's where the similarity ends!

Zircon was first found in Australia and is estimated to be 4.4 billion years old, and the natural gemstone is not very common, either. Cubic Zirconia, on the other hand, cubic zirconia (CZ) is a newcomer to the world of gemstones.

Zircon vs cubic zirconia: value

  • Zircon 1 carat = $70-$200 USD
  • CZ = $20 USD

A natural gemstone is always valued more than a synthetic. Zircon is substantially more expensive than CZ but much cheaper than genuine diamond. A carat is worth around $70-$200 USD depending on the amount of zircon and its quality.


A CZ is virtually useless in terms the cash, with a carat cost about $20 USD. CZ does have a lousy resumption as the stone is synonymous with the word fake. However, the quality and brilliance of the stones make them especially popular amongst jewellery collectors. 

Zircon vs cubic zirconia: clarity & colour

CZ has a clear ear of the eye, and it's almost always perfect. Its lack of deficiencies is a clear hint that it is accurate.

Zircon is typically colourless, sometimes known as white zircon, but also comes in yellow-golden, red, brown, blue and green.. It is commonly free of impurities and has an outstanding definition level, but some zircons have an opaque appearance, reducing their worth.

CZ is produced in labs, but the final result can be manipulated using manipulative techniques such as changing CZ.

Specific zircon stones have pleochroism (seen differently by different angles). Zircon receives its colour via the existence of trace elements during formation. Some are radioactive, but those in jewellery are made stable and safe.


pink CZ heart necklace



Pink CZ, also known as pink ice, is very popular in jewellery manufacturing. Other standard CZ colours consist of green, black, blue, orange and red. They both have excellent colour bands and look very similar to diamonds when colourless. Most of the stones are colourless to mimic the D class of diamonds.

Zircon vs cubic zirconia: durability

  • Zircon is rated 6 to 7.5 on the Mohs scale.
  • Cubic zirconia Mohs Scale 8.5

 Zircon cube reaches 6 to 7.5, which is a fair to good toughness on the Mohs scale and is suitable for daily wear. It is not easily chipped, damaged or scratched, so it is relatively stiff.

Over time the gemstone can get cloudy; therefore, regular cleaning will protect its shine.

Colourless zircon may look similar to a diamond. Still, it is a much softer and regulate stone, considerably weaker than a diamond and a little less durable than a CZ crystal.

Zircon vs cubic zirconia: beauty and brilliance

  • Zircon Refractive Index = 1.93 – 1.987
  • Cubic zirconia Refractive Index = 2.150 - 2.182 

The lab-created CZ has a higher sparkle, lustre and dispersion with a high refractive index. Cubic zirconia has RI 2.15- 2.18, a ratio greater than the zircon. So, if we look at brilliance, the cubic zirconia will pop up more.

Dephini Uses High-Quality CZ

white CZ crystal heart pendant

Browse our range of High-Quality CZ

At Dephini, we make fine jewellery in 925 Sterling Silver, Gold, and Rose Gold embellished with high-quality cubic zircon crystals for the most impact. We love working with the cubic zirconia gemstone as it provides the wearer with superior brilliance and sparkle, perfect for any occasion.

Check out our colourless gemstone range and our colour gemstones designed for pure elegance featuring one or two stones.

Frequently Asked Questions:

Are lab-created diamonds the same as cubic zirconia?

Lab-created diamonds are synthetic diamonds whose physical and optical characteristics are identical to those of genuine diamonds. Cubic zirconia doesn't offer the same properties as diamonds, with a bit of sparkle and fires the same way as diamonds. It's far more affordable than an ordinary diamond, yet you still have the beauty and extraordinary diamond shine. See this spectacular one-carat natural gem.

Can cubic zirconia get wet?

There's some cubic zirconia that can stay wet even if water becomes infested. Water containing chemicals and minerals like chlorine can impact the molecules in the crystal. Wearing any form of jewellery during hydro- activities can affect the quality. When water-related activities like washing up the dishes, bathing, or swimming, if possible, it is best to take the cubic zirconia jewellery off and store it in a dry area.