The Guardian Angel collection gives pawrents peace of mind with the magical and mystical protection of genuine crystals. Amethyst is known for its protective qualities and ability to transmute negative energy, helping your furbaby to feel safe and peaceful. Pets are easily effected by our emotions and amethyst shields them from absorbing too much outside energy. The high vibration of amethyst can help create balance and health on physical, emotional, and mental levels. It's light weight and durable to make it easy to enhance your pet's quality of life! 1/8" clasp opening fits around most collar loops