A bronze grid-like item covering an oval jade and looking like a tortoise shell was discovered during the latest excavation work at China's ancient ruins site Sanxingdui, the Sichuan Provincial Cultural Relics and Archeology Research Institute said on Monday. 

The institute called the item found in No. 7 pit the "treasure of the pit," citing its four bronze dragon head handles, at least two bronze ribbons, and a piece of embedded turquoise jade as unprecedented composition among cultural relics discovered at Sanxingdui.  

The remains of silk on the treasure boxes and jade articles probably indicate that the jade and bronze articles were wrapped with silk articles.   Archeologists suspect they were used for sacrificial purposes.

They expect to see whether the jade in the grid-shaped bronzes has decorations or silk fabrics on its back during the cleaning and restoration process. If written language is on the jade, it will be the largest such discovery at Sanxingdui because no writing has been found among the site's cultural relics.

(Cover image designed by Li Jingjie)