METHOD OF UTILIZING CONGLOMERATE AND SANDSTONE AS POLISHING AND CLEANING MATERIAL

PURPOSE:To obtain a polishing and cleaning material having a high hardness with little powdered dust scattering, for polishing and cleaning the outer surface of a metal or stone, by providing a polishing and cleaning material of a predetermined hardness and grain size made of a specified conglomerate and sandstone collected. CONSTITUTION:Conglomerate and sandstone are collected from the Neocene ''Goan'' layer or ''Taki'' layer, the Palaeogene ''Asagai'' layer or ''Sekiji (ash interposing)'' layer and/or the later Gretaceous ''Gyokuzan'' layer or ''Kasamatsu'' layer in Iwaki district or the south of Futaba area, Fukushima prefecture, Japan. Such conglomerates and sandstones are, after being carefully selected by flushing, treated through a process comprising the steps of self-grinding, preferential crushing, dehydrating and drying, and repeated screening, thereby to obtain a polishing and cleaning material having more than 7 at Mohs scale (hardness scale) and 8 to 35 mesh size.