Vintage fleur-de-lis clip on earrings with adjustable screw

These are vintage fleur-de-lis earrings on a royal blue background, the flyer-de-lis is raised. the back of them are extremely detailed with design. They are clip on with a screw which is adjustable for comfort. Not sure of date. They have markings that say pat.no 4.176.475 they have some discoloration on the gold tone