Abstract: A horology crystal (G) includes at least one portion having a minimum thickness of 3.5 mm in which there is formed a three-dimensional decoration that can be an internal laser engraving (S), a decorative item enclosed in the crystal (G) upon mould casting of the latter, or a plaquette of the same material of the crystal that is previously prepared with a print on the top surface and a print on the bottom surface and then subsequently integrated in the crystal (G) upon mould casting of the latter. Said horology crystal, preferably, has the shape of a spherical segment and is provided with a particular shaping along the bottom edge thereof and/or on the bottom, so that it can be removably mounted in the case (C) of a watch or wall/desktop clock.