The color-frosted Meinl Sonic Energy Crystal Singing Bowl is made of high-purity quartz to create a very pleasant aura with its sound and design. Its long-lasting, spherical tone spreads when the singing bowl is gently tapped or rubbed so that the energy can be felt in the entire surrounding. All Crystal Singing Bowls are delivered with a white silicone ring to avoid possible impact and to ensure the best resonance.