Grooved Trapezoid Object

This object id made of gray jade, with some brownish stains left on its surface by permeation. Its obverse side has five grooves with ridges between them. Its reverse side is flat, with intaglio border lines near the edge and short, decorative lines on both sides. The raised edges have eight small holes, and the body of the object has six large holes. This peculiar object is well polished al over. Archaeologists have found two such objects in the Jinsha site, the other with somewhat different grooves. It is the first time such objects were found in China. It is presumed that this object was sealed with leather to serve as a sheath for swords.