In regard to the way it feels, some words for sand are as follows: gritty, granular, and coarse. These words mean that the sand is rough (think of sandpaper).
In terms of size, sand can be described as microscopic because of all the tiny grains that go into the sand.
Lastly, although the color of sand varies, it can often be described as tan or cream-colored. These words mean that sand is somewhere between brown, yellow, and off-white.
