Natural Dyed & Heated Calcite Crystal Ball, Reiki Energy Stone Display Decorations for Healing, Meditation, Size: about 40mm in diameter.â»Please note that the healing properties of gemstone is not scientifically proven, but gemstone therapy meditation may induce a placebo effect that helps you relax the mind. Please Note: Because these balls are made by natural Citrine, the color could be slightly different from one batch to the next.