Large, unusually thin and highly translucent nephrite jade of pale celadon color with one more opaque "calcified" patch and darker streaks, the central hole beveled from one side. In Liangzhu style but almost certainly not that old, now in a fitted carved wood stand of later date. From a good New York City collection 20 years ago. Displays beautifully when backlit, and here's a front-lit view.