If you are browsing for a high-end replica of a Rolex Datejust with diamond hour markers, or perhaps a fully iced-out Audemars Piguet Royal Oak, a very practical question comes to mind: Are the stones on these super clones real diamonds?

In the world of 1:1 horology, where factories go to extreme lengths to reverse-engineer cloned movements and forge genuine 904L steel, the approach to gemstone setting is highly calculated. The short answer is no, stock factory super clones do not use natural, earth-mined diamonds. However, the technical reality of what they do use—and what collectors upgrade them to—is fascinating. Let’s look at the science behind the shine.

The Factory Standard: High-Grade Cubic Zirconia (CZ)

When you purchase a premium super clone straight from an elite factory (like Clean Factory or VSF) that features diamond hour markers or a diamond-set bezel, the stones utilized are almost exclusively high-grade Cubic Zirconia (CZ).

Why? It comes down to basic economics. A genuine factory Rolex Daytona with a factory-set diamond bezel costs tens of thousands of dollars just for the stones. If replica factories used natural diamonds, the clone would cost $5,000+, entirely defeating the purpose of the replica market. However, modern CZ used by top-tier factories is cut with precision faceting. To the naked eye, under standard indoor lighting, these stones provide an excellent approximation of a diamond's brilliance, though they lack the sharp refractive "fire" of a genuine stone under a jeweler's loupe.

The Enthusiast Upgrade: Moissanite

For collectors who want their watch to pass a standard diamond tester, the aftermarket upgrade of choice is Moissanite. Many custom jewelers take 1:1 super clone base watches and replace the factory CZ stones with VVS-clarity Moissanite.

Moissanite is a silicon carbide gemstone that is mechanically brilliant for two reasons:

• Thermal Conductivity: Moissanite conducts heat similarly to a natural diamond. Therefore, if someone puts a standard handheld diamond tester to your Moissanite-set watch, it will beep and register as a real diamond.
• Refractive Index: Natural diamonds have a refractive index of ~2.42. Moissanite actually exceeds this with an index of ~2.65. This means Moissanite is exceptionally "firey," giving off a highly scintillating rainbow reflection under light.

The Ultimate "Franken" Build: Lab-Grown Diamonds

At the absolute pinnacle of the custom clone market are watches set with Lab-Grown Diamonds. Unlike CZ or Moissanite, lab-grown diamonds are actual diamonds. They possess the exact same crystal lattice structure, carbon composition, and 10/10 Mohs hardness rating as earth-mined diamonds. They are just grown in a pressure chamber rather than dug out of the ground.

A 1:1 super clone customized with a lab-grown diamond bezel or dial is mechanically and visually identical to a retail piece. The stones behave exactly as natural diamonds do under magnification, lacking the exaggerated "rainbow" effect of Moissanite, and delivering the crisp, icy white brilliance that luxury brands are known for.

The Final Verdict

If you are buying a standard 1:1 super clone out of the box, you are getting high-grade Cubic Zirconia. It looks fantastic to the naked eye and keeps the watch affordable. However, if you are looking for that undeniable, tester-passing brilliance, upgrading to a custom Moissanite or Lab-Grown diamond build is the undisputed path for serious horology enthusiasts.