An article, which can be a watch, a piece of jewelry, a spectacle frame or a leather-ware item, for example, comprising at least one movable decorative element contained inside a housing (15) defined between two walls (5, 10) whose inner faces (5a, 10a) are parallel to one another, at least one (5) of these walls which is externally visible being transparent. This housing (15) encloses movable decorative elements (13, 14) each having an axis of revolution and two guide surfaces (14a, 14b), one of which is convex, respectively adjacent to said inner walls and being arranged to allow the movable decorative elements (13, 14) to move freely in translation and in rotation about their axes of revolution inside the housing (15). The internal faces (5a, 10a) of the housing (15) are dished with a curvature along at least one radius of curvature, which increases the glittering effect by increasing the speed of rotation of the mobile decorative element, such as a diamond.