Abstract: An aggregate washing and classification system incorporates into a water-filled receptacle a sand classifier and one or more rotating augers. The augers are wrapped with screens or perforated walls that are fixed relative to the augers. The size of the perforations may be chosen to selectively sift particular sizes of gravel and rock, and if the perforations increase in size along the length of the augers, either continuously or discontinuously, the material which passes through the perforations will likewise increase in size with greater travel through the auger passageway. Consequently, a set of rock bins may be provided adjacent to the auger outlet, for collecting various sizes of larger aggregate, such as washed rocks. Sand will typically be permitted to pass through the screen perforations near the aggregate inlet. Once outside of the auger and screens, the sand will drop directly into a sand classifier, which is conveniently located directly below the augers and adjacent to the material inlet.