The real thing is even more different than an ocean.
In an aquifer you have something like wet sand or wet rocks, i.e. there is sand/rocks and the water is in the space between them.
In this case, the molecules of water are inside the crystal structure. It's almost like a chemical reaction instead of only some inert object getting wet.
An usual similar compound is Cooper Sulfate that is nice because it changes color. The anhydrous version is white and you can get it heating the normal version. The normal version is blue and it has 5 water molecules per each CuSO4. But it is not wet like wet sand/rocks, the water is trapped inside he crystals. I can't find a good link but there is more info in https://en.wikipedia.org/wiki/Copper(II)_sulfate#Other_form_... there are some nice photos in https://www.google.com/search?tbm=isch&q=copper+sulfate+colo...