Divided by the diameter of the sand particles: giant sandstone (2 ~ 1mm), coarse sandstone (1 ~ 0.5mm), medium sandstone (0.5 ~ 0.25mm), fine sandstone (0.25 ~ 0.125mm), fine sandstone (0.125 ~ 0.0625mm), among the above sandstones, the corresponding grain size content should be above 50%.