This is done intuitively. When laying out the rings in a pattern on the floor or on a person's body, the health practitioner may adjust the beads to accommodate the client's own energy. It was discovered that the beads if not properly aligned created an imbalanced energy field, and so for non-health practitioners choosing to utilize the rings to charge food and water, and use on their own body, the beads were omitted. The technique of the double wound wire is the same in both ring designs. John Keely discovered that different metals possessed different vibrational properties.
Gold is vitalizing and energizing.
Copper is grounding, and the neutral. Silver is receptive and the feminine energy. The Caduceus rings use silver to supply the feminine component with all the gold plated Caduceus rings. In addition there are solid silver Caduceus rings which some people needing more of the energy of silver respond very well to. It depends on what the individual needs to balance their own aura.