This is a Chinese antique replica. Jade cong, commonly used in Liangzhu culture (about 2500BC, China) as sacrifice wares, is in prism form with a hollow round center. It shows ancient people's simple cognition of heaven and earth---round sky and square earth. String patterns appear around the surface and monster face design across the corners as decoration.
Length: 3.34inch, height: 1.575inch.