This is the seal of alchemy. It is actually a formula. The circle in the middle stands for the void (nothingness in a state of potential). the square around it represents thought…meaning that the thoughts activates the potential energy. The triangle represents intention (as added by universal energy or source mind) and the outer circle stands for manifestation. So it is basically a formula telling that thought creates reality… and the reason the inner and outer circle are the same shape, is because of the truth that everything-ness is nothingness. This symbol is from back in the day when it was a big secret that mind is actually what creates manifestation.