Colbalt beach glass pendant features a found piece of cobalt glass gently tumbled in the waters of the St. Lawrence River. It is inset in a silver plated hammered setting, and strung on an intricate 20" sterling silver (.925) chain with a lobster clasp. Cobalt glass is one of the rarer colors to find and is such a beautiful rich color for jewelry. What was this? Colbalt glass was commonly used for medicine or poisons bottles, Noxzema, Milk of Magnesia, and even Vick's Vapor Rub.