Zirconia, referred to as CZ: the best alternative to diamond

Nowadays diamond is the hardest, the purest and the shiniest precious stone. It is also one of the rarest: the reason is its creation process which requires from 1 to 3.3 billion of years… Needless to say that since its discovery almost 5 000 years ago, humans never stopped looking for a reproduction of this exceptional material.

Substitute of diamond created are numerous: firstly, strass in the 18th century in leaded glass, synthetic spinel, fabulite or even yag at the beginning of the 20th century… It is the cubic zirconia, created in 1973, which finally wins the heart of high jewellery. In fact, cubic zirconia, once shaped at the correct size, was hardly recognizable – even by professionals – due to the similarity in properties between diamond and CZ.

CZ under different angles

Strong resistance to high temperatures

With its great resistance to high temperatures, cubic zirconia is one of the best possible alternatives to diamond, especially for gem-setting. Far from the remarkable fusion temperature from the diamond culminating at 3 546,85°C, CZ can still be heated up to 2 680°C.

Its brightness and transparency

Refractive index of zirconium is 2.18, which puts it very close to diamond whose index is particularly high (2.41), giving it its great ability to reflect light. It is mostly the most appropriate cut of stones that will give it all its depth and brilliance.

Its sparkle, its rainbow light

CZ is also a synthetic stone with a wide dispersion (0.058- 0.066), even wider than diamond (0.044), which means it gives off a strong sparkle – it is said to glow with a thousand lights… This is what makes cubic zirconia so special compared to its competitors and makes it one of the best alternatives to diamond!

Its hardness

Besides, CZ is particularly resistant, unlike strass which is widely used in jewelry. On Mohs scale, measuring hardness of materials, it is indeed at 8.5 when diamond is at the maximum index of 10. In comparison, the synthetic crystal – as for Swarovski – has a hardness of 7. The higher is the hardness, the more intact in time will the stone remain: diamond for example will never show a scratch on its surface.

Its price

Scarcity of a material makes its price, diamond is not exempt from this rule with an average price between 5 000 and 6 000€ for a 1 carat diamond (0.2 gram). Its price is exponential according to stones ‘carat: the biggest is the stone, the rarest it is. In comparison, CZ is much more affordable with its 1€ per carat.

Finally, if diamond dealers have set up guarantee certificates for diamonds (based on the “4C”: cut, clarity, carat, color), cubic zirconia is now subject to the same requirements and expectations as the hardest stone in the world. Laser engraving, done on diamonds as a guarantee in addition to the certificate, has also been democratized for CZ with key players in the field like Preciosa and Dalloz!

However, if diamond and cubic zirconia are quite similar, these can still be easily differentiated through a precise analysis of their properties.