A luminous glazing unit includes a first glass substrate, made of mineral glass and in optical contact with a second glass substrate, a polymer layer, selected from a lamination interlayer, associated with a tinted and/or reflective element, and/or an opaque polymer encapsulation, a porous silica layer, underneath the polymer layer, a light source, optically coupled to the first glass substrate, and a light-extracting device associated with the first glass substrate, a mineral and transparent protective coating made of silica, directly on the porous silica layer and directly underneath the polymer layer.