grain shape

What Are 3 Types Of Grain Sizes? to 0. 0.5–1 mm. 0.020–0.039 in. Coarse sand. to 1. 0.25–0.5 mm. 0.010–0.020 in. Medium sand. to 2. 125–250 μm. 0.0049–0.010 in. Fine sand. to 3. What is grain size in geology? Grain size is the average size of the grains in a sediment sample. It is also