Sandstone would be a slightly darker colour than sand, it would turn into sand under pressure and would turn into sandstone from sand when you compress sand or add lots of water, it would erode very easily with acid. the metling temp would be the same as brick and it would break under pressure at 17 pressure. :D It would be SSTN
What uses it would have? I can't think of anything, except making pyramids and stuff, but you can just make the pyramids out of normal sand. So, no uses.
EDIT: Lol, I posted almost the same time as fast-driver
o___o
This is awesome :D But, I don't know if it'd be useful as a whole second element. It would also almost undoubtedly confuse many older saves that keep lots of sand in one place under pressure.
..Assuming there is a way to create sandstone that doesn't involve doing something weird to Brick, which would just be confusing. o_o
When melted then cooled....
Don't be a smartass..
It would become indestructible in ambient heat?
:P meanie