The roll-on bottle allows the oils to be applied precisely and easily to the skin. The ball is made of smoothly polished amethyst. The stones placed inside provide a unique visual effect, and it is also believed that they enhance the effect of the mixture. Amethyst is believed to have healing properties that protect the bearer against negative energies. The stone also brings clarity and peacefulness to the waking mind, and is said to control negative thoughts, promote wisdom, and help think more clearly. These Gemstone Roller Bottles are perfect for use with essential oils, perfume oils, DIY sample blends, essences, aromatherapy, and other liquids.