3.4 cm. Skoryl is the strongest protective stone acting as a shield against the negative environment. Protects against the radiation of monitors and computers (place the larger piece between you and the screen, the smaller boulder in your shirt pocket). It breaks down old blocks, allows brightness and positive energy to penetrate the body. It conveys a strong flow of spiritual energy, joy of life, vitality and inner security. Tourmaline also helps against dizziness, infection, multiple sclerosis, feelings of nausea and negativism, and strengthens memory. It promotes healthy sleep.