The pyramid represents the sense of harmony and unity within ourselves and with the environment to which we aspire. Pyramids amplify and then tightly focus energy through the apex. A crystal pyramid is used to draw off negative energy & blockages from Chakra centers. A gemstone pyramid will enhance & focus the inherent properties of the crystal.
Spheres symbolize wholeness. They can increase self-awareness and clear thinking and can help unify the mind, body and spirit. The power of the crystal is radiated outwards in all directions when they are in the form of a sphere.