Himalayan Quartz Rainbow Sphere: Ethically Mined Natural CrystalEthically mined Himalayan Quartz 70mm ~ 2 3 4" ~ 532 grams Hand mined high in the Himalayas, this is over half a kilo of bright and energetic Quartz sphere with beautiful rainbows. After holding quartz for half an hour, there is a measurable increase in alpha brain waves. Over a longer period of time, there is an increase in theta and delta brain waves. Alpha: ESP is initiated, and healing is enhanced at 7 14 cycles per second. Theta: Deeper state ESP