This item uses natural stones. The string is made of elastic rubber and is stretchy. Aquamarine: Approximately 10mm Inner circumference: Approximately 17.5cm 【Aquamarine】 Aquamarine, with its clear, refreshing blue color. It is called the "stone of the sea" and is said to calm the heart and facilitate communication. The pure blue color makes you feel light just by looking at it. ◇ Due to the use of natural stones, there may be chips, scratches, and variations in color. We hope you enjoy these natural characteristics. ◇ As this is a handmade item, please refrain from purchasing if you are looking for the perfection of a mass-produced product. ◇ There may be knots or cut ends of the string that are not tucked away, or are left as part of the design. ◇ The color of the product may appear different from the actual product depending on your device and environment. Each stone has its own unique color and pattern, making it one of a kind in the world. We hope you can casually enjoy these power stones, like a small amulet that accompanies you in your daily life. Please check the profile for bulk purchases.