Turquoise & Sterling Silver Tufa Cast BraceletSterling silver bracelet with 1" turquoise stone tufa cast cuff . The cuff is detailed with moon, stars, arrows and shapes that were carved into a tufa stone to create the cast for this whimsical bracelet. Tufa casting has been used for many years in Native American communities and beyond. It includes taking the tufa stone (volcanic ash composition) carving the desired detailing into the stone to create the mold, and pour molten silver to create the