Best Crystals for Studying and Learning - A Detailed Guide Black tourmaline is a great stone that aids the individual in improving his concentration power and calms the individual if he is present in overstimulating surroundings. Black tourmaline jewelry is also believed to bring success to the wearer while protecting him from negativity and acting as a shield against low vibrational energy. So, in case you have an exam that you are scared of, try working with a black tourmaline. There are various ways of using black tourmaline. For instance, you can wear it as black tourmaline jewelry or you can place a piece of black tourmaline crystal on your desk. It does not matter how you use it, black tourmaline will allow you to stay focused and stay centered as you prepare for your important exam.