The circle, the basic shape of the vast majority of rings, is itself a central design in sacred geometry.  The open circle symbolizes wholeness, completion, stillness within motion and a unifying order of cycles that repeat in time.  Circles are a pure distillation of both the shapes of the planets and their cyclical course through the sky.  Universally used as a symbol for the sun, the circle has therefore represented clarity, eternity, awareness, timelessness, completion with renewal, and the integrated self.  Keep your circle positive and create good karma!