I think they are all sold with documentation and serial numbers so they can be traced, you could take them to a reputable jeweler to get them checked :o)

Look for the sweep of the second hand. It should be heavy. It should have the Rolex logo on the winding knob. It should not say Made in China on the back. Your best bet is to take it to a respectable jeweler.

I know one way is to check that its second hand sweeps rather than ticks. Rolexes should possess a smooth sweeping second hand.

Probably one of the easiest ways to identify a fake Rolex is by the caseback. Counterfeiters will often use a clear display, or "skeleton" caseback, thus allowing you to view the inner workings of the watch. The problem is Rolex does not make such a watch, therefore, these models are easily identified as counterfeit.

The list of things to check • Has a Sweeping second hand(continuous motion instead of a ticking one). • Rolex never manufactured clear casebacks, it did not engrave them either. • Genuine models will have a smooth caseback, whilst fakes might feature engraved logos and other designs. •A real Rolex has a 3D hologram encoded sticker on the caseback. For models produced after 2002, a Rolex crown can be viewed on the sticker, and it changes patterns when you see it from different angles. A replica usually has a repetitious Rolex pattern printed on it, but does not change when viewed from other angles. •Rolex has introduced a tiny crown logo etched onto the crystal at the area around the six o'clock direction after 2002, so it should not be present in earlier models. •The crystal in authentic current date display models (with the exception of the Sea-Dweller) will have a Cyclops lens attached to the crystal, magnifying the tiny aperture 2.5 times. •Then there is the triplock crown seal. It can be identified by three very small dots positioned under the Rolex "crown" logo engraved on the end on the winding crown. •One of the most accurate ways to identify a counterfeit is by locating the Serial and Case Reference numbers engraved on the side of the case, located between the lugs. Engraving on a genuine Rolex features light-reflecting, very fine lines. A copy has a more "etched" appearance and the spacing in the numbers may be too close.

rolex is one of the last watchmakers to make all its own parts so if you open it up and use a lens you will see the rolex mark on each part of the mechanism

One of the easiest ways is to look at the flip clasp secondary latch. A Rolex is not drilled through for a rivet type of catching "bump". It has a piece of metal embedded on each side. Any replica I have ever seen is drilled through. Correct date magnification is another. Most replicas don't magnify enough. The back of the case will not have any lettering, and will be solid.