Fordite, also known as Detroit agate, Motor City agate, paint rock, or paint slag, is a lapidarist term for polished pieces of finely layered paint masses from automobile factories. The masses consist of automotive paint which has hardened sufficiently to be cut and polished. It was formed from the buildup of layers of enamel paint slag on tracks and skids on which cars were painted with acrylic lacquer, which have been baked numerous times. In recent times the material has been upcycled into jewelry.