Yoga Collection. "Aum" or Om, is believed to be the basic sound of the world. When chanted, it resonates throughout the body, and penetrates to the center of your being. Sterling Silver Tarma Charm is matched with our petite silver chain for an elegant look you can wear everyday! Charm is 12 mm in diameter (just under 1/2 inch) and 1 mm thick. Charm and chain are .925 Sterling. Chain is 18 inches long with a secure sliding clasp closure. Cast in the USA.