Lab-Grown Diamond or Moissanite: How Not to Confuse the Two

They both sparkle, they look alike at first glance, and they are often mentioned together. Yet, lab-grown diamonds and moissanite are two very different materials — and the choice between them deserves clarification.

Moissanite: what exactly is it?

Moissanite is composed of silicon carbide (SiC). It was first discovered in 1893 in a meteorite crater in Arizona — an extremely rare natural curiosity. Today, all moissanite sold in jewelry is synthesized in a laboratory.

It is not a diamond. Nor is it a cheap imitation. It is a material in its own right, with its own properties — different from those of a diamond.

Composition: a fundamental difference

A lab-grown diamond is composed of pure crystallized carbon — exactly like a natural diamond. It is this structure that gives it a hardness of 10/10 on the Mohs scale, the maximum value, and permanent durability.

Moissanite is composed of silicon carbide. Its hardness is 9.25/10 — very close, but not identical. In daily use, the difference is minimal. That's not where the real distinction lies.

Brilliance: similar but recognizable

This is where the difference becomes visible.

Moissanite has a higher dispersion index than diamond — meaning it produces more colorful rainbow effects in bright light. For some, this is attractive. For others, this sparkle is perceived as too intense, too glittery, sometimes described as artificial.

Diamond produces a white sparkle, more classic, more discreet in its brilliance. It's a matter of taste — but it's a real difference that many people perceive, even without being able to name what they see.

Certification: a decisive point

A lab-grown diamond can be IGI or GIA certified according to the same criteria as a natural diamond: carat, color, clarity, cut quality. This certificate is an official gemological document, verifiable online, with a laser-inscribed number on the stone.

Moissanite is not certifiable by these organizations. It may come with a manufacturer's certificate — but this is not the same as an independent gemological certification.

At Diamelys, every diamond comes with its IGI certificate. This is your guarantee that you are buying a real diamond, with verifiable and objective characteristics.

Price: the advantage of moissanite

Moissanite costs significantly less than a lab-grown diamond — often five to ten times less for an equivalent size. This is its main appeal.

That said, lab-grown diamonds already cost 40 to 70% less than an equivalent natural diamond. The price difference between moissanite and lab-grown diamonds is real, but it must be considered in light of what you are actually buying: a simulant on one hand, a real certified diamond on the other.

Which to choose?

If your absolute priority is the lowest possible budget for a visual effect close to that of a diamond, moissanite may be suitable — especially for jewelry worn occasionally.

If you want a real diamond, certified by an independent organization, with classic brilliance and maximum durability, a lab-grown diamond is the answer — at a much more accessible price than a natural diamond.

Both are legitimate choices. What is not acceptable is to confuse them — or worse, to sell one for the other.

Frequently Asked Questions

Is moissanite a diamond?
No. Moissanite is composed of silicon carbide (SiC), while a diamond is pure crystallized carbon. They are two distinct materials with different properties.

Can you tell the difference between moissanite and a diamond with the naked eye?
Often yes, in bright light. Moissanite produces more pronounced rainbow flashes than a diamond. A trained eye will notice it, even without equipment.

Is moissanite IGI certified?
No. IGI and GIA only certify diamonds. Moissanite may come with a manufacturer's document, but it is not an independent gemological certification.

Is there a significant price difference between a lab-grown diamond and moissanite?
Yes. Moissanite is generally five to ten times cheaper. But lab-grown diamonds are still 40 to 70% cheaper than natural diamonds — which already makes them a very accessible option for a real certified diamond.

Questions about our IGI-certified lab-grown diamonds? Our team is here to help →