A Mystic Rectangle occurs in an astrological chart when four or more planets are connected by oppositions, sextiles and trines. To get a better idea of this, picture a long box, or rectangle, with two long sides and two short ones, and with the diagonal lines drawn in across the center of the box.
The four corners of the box represent the four planets involved in the Mystic Rectangle; the short sides of the box represent the sextiles; the long sides represent the trines; and the diagonal lines crossing each other in the middle are the oppositions. This results in six related aspects among four or more planets -- two oppositions, two sextiles and two trines.
Sextiles and trines are ‘soft,’ or beneficial, aspects, and oppositions are ‘hard’ ones that can cause conflict. But since there are four soft aspects and only two hard ones in a Mystic Rectangle, the overall effect of this configuration is considered helpful -- with just enough of a challenge thrown in by those two oppositions to keep things interesting!
Due to the layout of the planets in a Mystic Rectangle, they’ll almost always lie in signs that complement each other. This will further affect the beneficial influence of the Mystic Rectangle as a whole.
Someone with a Mystic Rectangle in their chart will feel the effects of four planets working together in a strongly balanced and integrated pattern.
This configuration offers the bearer a chance at inner harmony -- if the challenge of those two oppositions can be faced and dealt with consciously.