Dear Rabbi

I work with baale Teshuva in Bogota, Colombia.

Its writed in Talmud Yersuhalmi Nedarim 3:2 “There is nothing square in the nature”

But you can see in Internet Salt Cubes in the dead sea (wich sides are squares). Also there are the some stones like pyrite, that are cubes. So it is not a proove that there is a mistake in the Tora?