Yin Yang BA GUA Eight Trigrams Amulet Green Quartz Magic Pendant Necklace Best Amulets Collection. Yin Yang BA GUA Eight Trigrams Amulet Green Quartz Magic Gemstone Stainless Steel Circle Good Luck Powers Pendant NecklaceYin Yang BA GUA Eight Trigrams Amulet Green Quartz Magic Pendant Necklace Gemstone Circle Size: 30mm (1 1/4"). Made from Natural Gemstone and holds permanently attached Yin Yang BA GUA Charm. Comes with Adjustable cord, and adjusts from 15 inches up to 24 inches. Comes with Branded Packaging