These days, when you are choosing a piece of jewellery with a colourless gemstone, there are several different stones fighting for your attention. In addition to classic natural diamonds, there are also diamonds which have been created in a lab, moissanites as well as cubic zirconias. Is it possible to tell the difference between these gemstones with the naked eye? And how to choose the one that not only suits your needs but that you also feel a connection to.
Natural diamonds: treasures hidden in the depths of the earth
If we had to describe a diamond in one word, we would call it timeless. Since time immemorial, diamonds have symbolised tradition, luxury and lasting value, which is why they rightfully hold a prominent place in our portfolio. Diamonds have a long history which has endowed them with many legends and symbolisms. They were most often associated with the idea of love and this has made them the first choice for engagement rings.
Natural diamonds stand out for their high price which reflects their exclusivity and rarity. Diamonds are mined and up to a tonne of rock has to be dug up to produce a single carat (0.2 grams) of diamond. What’s more, only 20% of the stones which are mined are suitable for jewellery making. The money invested in diamonds is however a sound investment.
You can find out more about how diamonds were created and how they end up in the hands of customers in our article on the origins of diamonds.
On the Mohs scale of hardness, the diamond is the hardest mineral on Earth. It is very resistant to damage, which gives diamond jewellery the badge of being immortal.
Laboratory diamonds: a true miracle of modern technology
While natural diamonds were formed Onbillions of years ago deep in the Earth's crust under extreme pressure and high temperatures, the story of lab grown diamonds for jewellery making purposes only started a few years ago. It should be stressed that both types of diamonds are real diamonds. Thanks to the progress made in science, we simply distinguish under what conditions they were created.
Lab grown diamonds share the same chemical composition and even completely identical physical and visual properties with natural diamonds. Where they differ, on the other hand, is in the clarity and perfection of their internal structures. And clarity is one of the main criteria when grading diamonds. Another important difference is the price: lab diamonds usually cost 20-50% less than natural diamonds. So it’s this combination of high clarity and favourable price where the greatest advantage of laboratory diamonds lies. You no longer have to compromise on quality when buying a piece of jewellery with a large stone. Jewellery with distinctive, premium quality diamonds is no longer an unaffordable luxury for a select few.
Natural and laboratory diamonds react in the same way when tested with a diamond tester, which is commonly done in jewellery stores. Special instruments in gemological laboratories are therefore needed to determine the origin of the diamond. These examine the stone for trace elements, crystal growth and other parameters. Even for laboratory diamonds, certificates are issued by international laboratories which state that the diamond is of genuine laboratory origin (in the case of KLENOTA diamond jewellery, these are IGI and GIA).
Moissanites: a stellar sparkle at your fingertips
In 1893, when French chemist Henri Moissan was examining rock samples from a meteorite impact crater in Arizona, he discovered microscopic parts of a gemstone he had originally identified as a diamond. It was only chemical analysis a few years later that revealed the differences in its structure. Coincidentally a mineral with the same composition had also been created in a laboratory, in fact only some two years earlier.
While the building block of diamonds is only carbon, the structure of moissanites also contains silicon along with carbon. Moissanites are apparently found in the universe near stars which is why they have earned the nickname stardust. The gemstone is only rarely found in nature. Jewellers today work almost exclusively with lab created moissanites, which have become much sought-after gemstones because of their properties and resemblance to diamonds.
While diamonds have the highest possible hardness, at 9.25 on the hardness scale, moissanites are a close second. They leave behind even rare gemstones such as sapphires and rubies. They are therefore very durable stones suitable for everyday wear. Moissanites also characteristically have a high lustre which is up to 18% bigger than that of diamonds. Their reflections can appear iridescent under certain conditions and this is due to the fact that moissanites are double refractive, whereby light penetrating the stone bends and refracts into two rays which are further broken down into spectral colours. If we were to rate moissanites in terms of clarity on a scale designed for diamonds, they would average a grade of VS. This grading is found in only 10% of diamonds.
Cubic zirconias and their fading glory
Cubic zirconias are still probably the most common material used in the jewellery industry to imitate diamonds. Sellers refer to them in various ways but most often you will see them labeled as CZ, cubic zirconia or inaccurately also as zircon. From a chemical point of view, cubic zirconias are zirconium dioxide which has the symbol ZrO2. They were previously unrivalled as an imitation of diamonds due to its hardness of 8.5 and high refractive index. These days cubic zirconias can in many respects be considered an outdated material.
And in fact, they don’t even come close to the visual qualities of diamonds. They often give off a glassy impression due to optical anomalies called "windows". These are transparent areas that do not reflect light which means that you can look through them like a window or conversely, they create black areas in the stone. This negative effect (known as windowing) is most apparent when you view the mineral from different angles. Another huge disadvantage of zirconias is that they lose their attractiveness over time - they become cloudy and cease to sparkle. We therefore do not recommend them for real jewellery which is meant to make lasting memories and delight for many years to come.
Zircons: the forgotten gemstones in the shadow of cubic zirconias
At this point, it’s worth mentioning zircons which are high-quality and very worthy natural gemstones that are often confused with cubic zirconias. Zircons are found naturally in a wide range of colours from brown, yellow-brown and yellow through to pink, blue, orange, grey, red, green and colourless. The rarest specimens are blue. On the hardness scale, zircons range from 6.5 to 7.5. Colourless white zircons are called Matura diamonds and were formerly used as imitation diamonds. However these days, due to the availability of more advanced technologies, other synthetic materials are used for this.
For a more detailed comparison of the basic properties of all the gemstones mentioned, please refer to this summary table:
Which gemstone to choose for an engagement ring?
We expect an engagement ring to retain its beauty for many, many years after the wedding, even with daily wear and minimal care. It’s therefore very important that the gemstone set in the ring withstand external forces well and is not prone to scratches and other damage. These needs are best met by diamonds - both natural as well as lab-grown.
Beauty is of course a largely subjective concept. Certain optical qualities such as clarity and lustre can be measured and compared, but no one can tell you whether a particular woman will like a white diamond, an iridescent moissanite, or a pink sapphire. But it is not by chance that diamonds are called the kings of all gemstones. Their beauty is simply dazzling.
But jewellery isn't just about what's visible to the eye. Diamonds, which have been associated with the theme of love and marriage proposals for centuries, will be an obvious choice for lovers of traditional values. Natural diamonds can also be seen as an investment as their value increases year on year. Unlike lab-created stones, the deposits of natural diamonds are limited, so these gemstones retain an aura of uniqueness and exclusivity. Moreover, many women simply long for real diamonds.
The favourable price and therefore the potential to get a ring with a large, high quality stone are the advantages of lab grown diamonds.
But we definitely don’t recommend saving too much on an engagement ring and for this reason cubic zirconias and zircons should therefore be avoided.
Moissanites are very interesting, high-quality and beautiful stones that could certainly adorn an engagement ring. Like colour gemstones and fancy diamonds, we see them as an interesting alternative to classic diamonds.