How sad is that? Well, I was about to create new planetary squares for Uranus, Neptune and Pluto, thinking it's an easy deal. Unfortunately I just read in J. Vesely's book about this problem.
I originally thought that these planets will just continue in the Chaldean sequence, giving number 10 to Uranus, 11 to Neptune and 12 to Pluto. Unfortunately J. Vesely is right that the Chaldean sequence shows the planets in the order from the further to the closer (or as Chaldeans believed). That means the numbers should be 2,1,0 and you cannot make Magick squares from these numbers. J. Vesely describes a method how different numbers could be extracted but I have to research that one more before I will finally get myself some sweet new planetary squares.
In the meantime I might post something about 3 philosophical principles, also known as the principles of alchemy (mercury, sulphur, salt) and their relation to the elements as it is something not so widely available on the internet.