A Pile of Sand is an extremely abundant/common resource in Survival 303.
Sand is a raw material that is one of the most abundant in the game, found on beaches and Desert island. Sand is useful for three things: production of sandstone and all items related to it, producing glass, and rudimentary construction of structures due to the extreme abundance of sand. As such, sand is useful for a wide variety of buildings, but is not attractive for trade due to its ridiculous abundance. Unlike most things which can be harvested, sand is gathered by clicking on any sandy beach with the Gather tool, which do not run out. It does not appear as a proper block until placed.