The order of Allah's creation - problem

Assalam w Alaykum brothers and sisters,
I was reading the "The islamic educatiOn series" and it said that Allah first created water and then the thrown, and then the guarded tablet and then the upper pen. No problem with that, but it says that the Guarded Tablet is a white pearl and the edges are made out of red ruby....
After, it says that Allah created the earth, the Seven Heavens and at last , rivers , mountains and the like.
So my question is : how can the Guarded Tablet be created with white pearl and red ruby if those rocks ans elements were put on earth after the creation of the earth which is later than the creation of the Guarded Tablet.
Thank you very much