Wuling keel stone is produced in Wuling Shangou River, Xiangxi Autonomous Prefecture, Hunan Province. The stone is hard, and you can hear the crisp and pleasant sound when you tap it with your fingers. There are holes in the stone body, holes in the holes, and holes are connected in series; Mostly reddish brown, deep and shallow, deep to purple; The stone is covered with red silk lines, colorful and beautiful; Unique shape, exquisite, smooth twists and turns, natural and soft, very similar to animal bones; It is thin, wrinkled, transparent and leaky, hence the name keel stone.