The mandala is one of humankind's most ancient art forms. With the circle as its basis, it reflects eternity and all of nature: the sun, the moon and even the bird's nest. Types of mandalas may be found in all religions, as well as in psychology. The word "mandala" is Sanskrit for "circle." According to mandala artist Charles Gilchrist, creator of "Sacred Geometry," a wandering guru may have brought the first meditation mandalas to Tibet in about the eighth century. Mandalas have been found…