As one of the most popular wristwatches, many perfect fake Rolex watches have been copied. So in order to eliminate the imitation of their products, Rolex gradually started to set a micro symbol of the crown at 6 o’clock position on the sapphire crystal.
Many watch lovers reacted that they didn’t see this crown secret, suspecting that their watches are fake. But in most cases, it is only because that the method is wrong. Since the crown is engraved by laser on the inside of the sapphire, which can only be seen under certain light. Meanwhile, the size is small, so it is easy to be ignored. The easy method to check it is to light from the horizontal side in a dark environment.
But strictly speaking, not all the watches of Rolex have been set with this tiny crown. For example, the cheap Rolex Milgauss copy with black dial has been engraved with such a symbol to identify the authenticity.