The roll-on bottle allows the oils to be applied precisely and easily to the skin. The ball is made of smoothly polished black tourmaline, and the stones placed inside provide a unique visual effect. It is also believed that they enhance the effect of the given mixture. Black Tourmaline is said to be a good stone for those who are sensitive to electromagnetic radiation and for those working on spiritual development. It is also believed to help overcome fear and anxiety, while enhancing self-confidence. Fill these Gemstone Roller Bottles with anything you desire. They are perfect for essential oils, perfume oils, DIY sample blends, essences, aromatherapy, and other liquids.