It was his belief that it was the geometric shape, not the material which was most important. However, according to John Keely, and Edgar Cayce, copper has its own vibration, or energy, which is considered to be grounding. It also acts better as an antenna channeling the Life force energy from the etheric realms into the physical. With the addition of the twisted caduceus wire, there is additional effect and benefit. We have them plated in silver and gold as well for those who wish to incorporated the vibrations of those metals into their aura, and into the field of the Genesa.
Copper is strong and grounding.
Silver is feminine and receptive. Gold is vitalizing. See what kind of jewelry you are attracted to as an indication as to what vibration you may be needing. Or you can dowse with your pendulum or muscle test to see what is best for you. One man in Oakland placed a rose quartz crystal inside the Genesa crystal and discovered that it broadcast the amplified energy of the rose in all directions.