What effect do you mean? If it is for Feng Shui purposes, the more transparent the better, or a crystal ball with strange images is also a good choice. Cotton wool is actually hard to avoid. If you are using it for personal spiritual practice or meditation, it does not have to be very transparent. See if the cotton wool, ice cracks, and visions in the crystal ball can enhance your intuition and ability. Touch it with your hands. Whether the sense of energy is strong is more important than transparency. Bingzhou stone balls are low in price and are not part of the crystal family, so their efficacy cannot be compared with white crystal. If you buy it just for the beautiful pictures, you can still buy the iceland stone ball because it is high quality and low price. If you buy it for the uses I mentioned above, then buy a white crystal ball!