back to What is Lab-Grown?

What is a Synthetic Diamond? How Do Simulated Diamonds Compare?

by Clean Origin
Last updated on August 26, 2023

What sets synthetic diamonds apart from simulated diamonds? Here, we explain what distinguishes simulated diamonds and synthetic diamonds and how to make sure that you’re getting the right kind of stone to fit your needs.

Simulated Diamonds

Lab Diamond Engagement Rings
Lab Diamond Engagement Rings

What is a diamond simulant? Simply put, a diamond simulant is a non-diamond masquerading as a diamond. In other words, it’s a stone or other material that mimics the general appearance of a diamond but does not have the same physical or chemical properties.

You’ve likely heard of a few different kinds of diamond simulants, including cubic zirconia and moissanite. Man-made diamond simulants are common. However, there are also a few natural gemstones that can fall into this category because of their clear, colorless appearance. These include quartz and white sapphire.

Synthetic Diamonds

Lab Grown and Mined Diamond Comparison
Lab Grown and Mined Diamond Comparison

Synthetic diamonds, on the other hand, are chemically, physically, and optically the same as mined diamonds. To reiterate: A synthetic diamond is a real diamond.

Also known as lab grown diamonds, man-made diamonds, or cultured diamonds, these diamonds have the same chemical composition, brilliance, and unyielding hardness as natural diamonds. The only difference is that synthetic diamonds are created in laboratories. The growth process goes under controlled conditions that mimic the same natural processes that create diamonds deep beneath the ground. Furthermore, lab grown diamonds display components that make them indifferent from naturally formed diamonds.

The most common types of synthetic diamond synthesis are Chemical Vapor Deposition (CVD diamonds) and High Pressure High Temperature (HPHT diamonds). These processes use different quantities of diamond seeds, pure carbon atoms and create a multitude of diamond crystals.

Interestingly enough, although lab grown diamonds are synthetic (meaning man-made rather than naturally occurring), the Federal Trade Commission has actually ruled it deceptive to classify a lab created diamond as ‘synthetic’ since this term can be misleading. They want to ensure that buyers of lab diamonds know that they are getting the real thing rather than a poor substitute. For the most part, you will find these diamonds labeled by one of their more appropriate names: lab grown diamonds, man-made diamonds, or lab created diamonds.

How Do You Tell the Difference?

Bezel Setting
Bezel Setting

There are various properties with each type of stone that will allow you to tell if it is a diamond simulant or a synthetic diamond (even a natural diamond).


Natural diamonds, and therefore synthetic diamonds, are the hardest minerals found on earth. On the Mohs Scale of hardness, they score a perfect 10. This means that the only thing that can scratch a diamond is another diamond.

Moissanite, one of the most popular diamond simulants, is a fairly hard mineral. It, however, is not as hard as a real diamond. On the scale, they score a 9.25, meaning they can be scratched by other elements. Cubic zirconia, on the other hand, scores an 8.5. This means it is much softer than a diamond and can easily be scratched. Those who use these simulants in rings or other jewelry may discover that the stones end up looking kind of beat up after extended wear.

Refractive Index

In technical terms, the refractive index describes the speed of light as it slows down to pass through a transparent or semi-transparent material. In layman’s terms, and when it comes to a diamond simulant and synthetics, it basically describes how the stone will reflect light.

The refractive index of a diamond is 2.4. This means that light travels through a diamond at a rate 2.4x slower than it does through air. Now, this is still far too fast for the eye to really capture, but the speed of the light as it passes through the stone can have some interesting effects on the shine of the stone. In comparison, the refractive index of moissanite is anywhere from 2.65-2.69. This can actually cause the stone to give off a ‘disco-ball’ appearance, as the shine can be overbearing at times. Since cubic zirconias are lower on the index than diamonds(sitting at 2.15-2.18), they reflect an excess of colored light, resulting in a ‘rainbow effect.’


Since a diamond simulant is not a real diamond, it costs quite a bit less. You could easily find moissanite that resembles the size of a 2-carat diamond for less than $1,500. Cubic Zirconia is even less valuable and can range anywhere from $30-$200, depending on size. A diamond simulant does not have a ton of market value. However, they’re a great option if you’re tight on budget.

Synthetic diamonds also cost less than natural diamonds, but the difference isn’t quite as extreme. That said, lab grown diamonds or synthetic stones can be anywhere from 20-40% less than mined diamonds of similar quality, which still makes them an attractive option for those who are hoping for real diamonds at a lower cost. However, since they are chemically, physically, and optically the same as mined diamonds, they still hold high market value. A 1.54 ct round stone with F color, VS2 clarity, and very good cut grade can start around $3,240. For a similar mined diamond, you’re looking to start around $5,900. Clean Origin also offers extremely competitive rates, even in the man-made industry.

It’s important to understand the difference between a diamond simulant and a synthetic diamond before you start your engagement ring search. If you have an extremely tight budget, a diamond simulant can be a good starting point or placeholder. Since synthetic diamonds are identical to mined diamonds, these gems are a wonderful mined diamond alternative if you’re conscious about ethically sourced jewelry and eco-friendly products.