Geological sieves are used for the estimation, analysis and sorting of sedimentary particles. All sediments, including, sand, soil, gravel etc. are composed of numerous grains. Calibrated sieves (sieves made to an internationally accepted scientific standard) each have a range of mesh sizes, when stacked on top of each other, the particles drop through the mesh with the larges ones being caught above the mesh, thus sorting the particles by size. All of our sieves meet ISO standards.