PEACE AND TRANQUILITY JADE PI DONUT DISC PENDANT ON ADJUSTABLE CORD Jadeite Donut Pi Disc Pendant (hand carved jade pendant from Burma). Burmese Nephrite jade, (a silicate of calcium and magnesium), is the historical Chinese Jade, or Stone of Heaven, a stone revered by the Chinese for more than 5000 years. Nephrite is prized for its special qualities: its extreme toughness, (the toughest of any natural stone), its alluring translucency and a smooth polished feel.All natural, not treated nor enhanced. On a smooth adjustable cord, with a max. length of 70cms (27 inches).