No, sandstone is not all the same size. Sandstone is a sedimentary rock formed from cemented sand grains. The size of the sand grains varies depending on the environment where it was formed and the processes that shaped it.

Here's why sandstone sizes vary:

* Grain Size: Sand grains themselves can range from very fine (like silt) to coarse (like pebbles).

* Clastic Texture: Sandstone can be classified by its texture, including fine-grained, medium-grained, and coarse-grained. These classifications directly relate to the size of the grains within the sandstone.

* Geological Formation: Sandstone formations can be small, localized outcroppings or massive, widespread layers spanning many kilometers.

* Erosion and Weathering: Over time, sandstone is subject to erosion and weathering, which can further change its size and shape.

Therefore, sandstone comes in a wide range of sizes, from small pebbles to massive formations.