Ok, historical bit #1, the pattern is taken from a popular european middle ages grimoire called the Key of Solomon. Grimoires were beooks of magic that reached their peak of popularity at about the same time as alchemy, this is why and Full Metal Alchemist fans should be familiar with these kinds of patterns.
The pattern on the door is the insignia of the school I went to in Japan.
the pattern is warped from a circle to a diamond, simplified for the sake of my sanity, and a few of the symbols are changed around (I added in my personal mark to the array. So its not a replica of the cirles they used. but yeah, grimoires are fun, and their kind of magic is under represented in fantasy since it takes more preparation and has less flair than sorcery style stuff.