The present invention relates to a method for producing crushed sand using clay mineral and limestone containing gemstones and an apparatus thereof, which are provided to eliminate the problems in which, when producing crushed sand by a general wet process using waste stones in a limestone mine, productivity is lowered by a build-up phenomenon in sand sorters, dehydrators, or the like since a reaction is undergone with water due to limestone or clay mineral contained in waste stones, and the produced crushed sand contains dust fines and thus falls short of the KS standard for crushed sand. The method comprises: a step of grinding raw stone dusts of waste stones mined from a stony mountain, and then primarily washing the ground stone dusts to supply raw materials; a step of gravity-sorting the supplied raw materials into particles with a grain size of 2 mm or less having a large amount of dust fines and particles with a grain size of 2 mm or more having a small amount of dust fines by a gravity sorter; a step
