These black ceramic doorknobs are reproductions of antique originals. They are molded of clay and then fired in an oven to set the glaze. They pair well with with brass rosettes and back plates. Sold as a pair with a spindle that will adjust to the thickness of your door.
Mortise Type Black Ceramic Doorknobs with Brass Ferrules
2 1/8" diameter with a 5/8" ferrule