Abstract: The invention relates to an ornamental device (1) comprising at least one cut or polished stone (2) with at least one rear portion (23). This ornamental device (1) is characterised by 5 the fact that it also has: means (3) to at least partially protect the rear portion (23) of the stone (2) from becoming soiled. This means of protection (3) takes on the shape of this rear portion (23) of the stone (2) and equips this rear portion (23) of the stone (2) without adhering to it; means (5) to prevent the ingress of a body from between the rear portion (23) of the stone (2) and the means (3) for protecting this rear portion (23) of the stone (2) and/or to prevent the egress of such a body from a defined internal volume (4) between the rear portion (23) of the stone (2) and the means (3) for protecting this rear portion (23) of the stone (2); Means for securing, on the stone (2), means (3) for protecting the rear portion (23) of this stone (2).