By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. View our Privacy Policy for more information.


Lab grown diamonds and diamond simulants are often wrongfully lumped together as the same thing. A bit like how you might say that sugar and salt are the same thing. They might look similar, but they still have their visual differences, and definitely are not made of the same thing. So what are lab grown diamonds, what are diamond simulants, and what are the differences between them?

Lab Grown Diamonds

We have already written quite a comprehensive article about what lab grown diamonds are which you can read up on. In summary, lab grown diamonds are real diamonds, just as real as natural diamonds mined from the earth are. They are chemically, physically and optically identical to one another, made up of carbon atoms in an isometric crystalline structure. No matter how you test a lab grown diamond, it is a real diamond through and through. And they are certified all the same as a natural diamond by the same labs with the same parameters. Lab grown diamonds are certainly not distinguishable from natural diamonds by the naked eye, nor through magnification.

Diamonds display a signature sparkle and brilliance which is unique only to themselves. While diamond simulants might look similar, nothing beats the real thing. And the fact that we are able to grow our own diamonds, bypassing all the unethical practices and destruction of our environment, is truly a blessing to the industry.

Diamond Simulants

Diamond simulants, also known as imitation diamonds, on the other hand are something else altogether. Simulated diamonds encompass a huge spectrum of synthetic materials, gemstones and glass. But they all share a common trait, which is that they are visually and compositionally different from a real diamond. The most common diamond simulants used are cubic zirconia  (CZ), moissanite and glass (also known as crystal). Other simulants include zircon, colourless sapphire, synthetic rutile, gadolinium gallium garnet (GGG), and yttrium aluminium garnet (YAG).

As diamond is the hardest material in the world, it is safe to say that diamond simulants are not as hard, making them more susceptible to wear and tear, collecting scratches and abrasions along the way, and are thus less durable. Due to their lack of hardness, it is also harder to achieve a high polish on the surface, resulting in some simulants lacking in the lustre of a diamond. As carat is representative of weight, and not size, the different simulants have different densities which can result in different sizes from a diamond despite having the same carat weight. There are too many variables to consider when we are looking at the different diamond simulants, so we are just going to cover the 2 most commonly used simulants - cubic zirconia and moissanite.

Cubic Zirconia

Cubic zirconia is a synthetic gemstone made of zirconium dioxide in cubic crystalline form. CZ is also susceptible to yellowing over time, which is probably where many of the false rumours of lab grown diamonds losing their shine or colour come from. It is one of the cheapest simulants around where a 1 carat example could cost as little as just $20 and a 2 carat example being $30. The easiest way to tell CZ apart from a diamond is the way it disperses light. When viewed under natural light, a diamond gives off white light whereas cubic zirconia emits a rainbow of light. This excessive display of light and fire is indicative that it isn’t a diamond.

However when viewed more closely, cubic zirconia actually displays less brilliance than a diamond due to its lower refractive index of 2.15 as opposed to a diamond’s higher refractive index of 2.417. This means that more light passes through the cubic zirconia whereas more light is reflected back to the viewer in a diamond.

As cubic zirconia measures a mere 8.5 on the Mohs hardness scale as opposed to a diamond’s 10, it is comparably much softer than diamond and prone to scratches and abrasions, making it a poor choice for precious jewellery due to its lack of durability.


This is perhaps one of the more premium diamond simulants in the market where 1 carat can cost you about $600. Moissanite is made of silicon carbide, and is often made in the lab. Natural moissanite exists but it is extremely rare. It was first discovered in 1893 by Henri Moissan who found what he thought was diamonds in a meteorite that had landed on earth.

As moissanite has a refractive index of 2.65, it possesses more brilliance than a diamond which can produce a disco ball effect of rainbow flashes. It can also appear fuzzy in certain angles due to this very nature caused by doubling of its back facets. Moissanite rates 9.25 on the Mohs hardness scale which is quite hard, giving it quite a lot of durability to be worn as jewellery.

Which is better?

At the end of the day, what you choose should be based on an informed decision. Each of the options mentioned in this article has its own pros and cons. Assuming that there are no budgetary constraints, going for a lab grown diamond is a safe option as it is a real diamond and has a light character that behaves as such, while at the same time having traceability of origin since it is grown in a lab, perfect for the eco conscious. However, if one has financial constraints, we do not recommend our clients going beyond their financial means just to get a diamond. There are more meaningful things in life than owning or proposing with a diamond, and your partner shouldn’t choose to be with you just because of a diamond. Diamond simulants are a great choice for those who do not have the budget but still want something that represents a diamond, and in fact, simulants like cubic zirconia and moissanite are mostly critiqued for looking “too good” as being a tell tale sign of an imitation diamond.

Everything has its place on our earth, and as long as our decisions leave the world a better place, that is what we stand for. That is how we started our search for The Better Diamond.