Here's a breakdown of the size categories:

* Very fine sand: 0.0625 mm to 0.125 mm

* Fine sand: 0.125 mm to 0.25 mm

* Medium sand: 0.25 mm to 0.5 mm

* Coarse sand: 0.5 mm to 1 mm

* Very coarse sand: 1 mm to 2 mm

It's important to note that these are just general guidelines, and the actual size of sand grains in sandstone can vary depending on the specific type of sandstone and its formation process.