Heheh, as you have noticed in another thread, I'm submerged in everything, that has near or far to do with erosion... hence also sandstone.
Isn't it a fact, that the sandstone naturally has seashells in it dues to it having been formed at the bottom of the sea? I think I have read about this, when the "pyramids made of concrete" debate raged on, and how the Egyptians (in case of the pyramid being of manmade concrete) would have been forced to put the seashells into the "mixture".
Anyway and in anycase, these seashells exist in the pyramid blocks, but I always imagined, that it would concern the whole building and uniformely... yes? no?

Ritva