As he dunked them into the water, he felt something graze his hand, pulled it out, and brought it home to show his dad, reports Xinhua.

Now experts say “it” turns out to be a 3,000-year-old bronze sword, probably from either the Shang or Zhou dynasty—”the dawn of Chinese civilization,” as the BBC puts it.

The head of the Gaoyou Cultural Relics Bureau thinks the 10-inch sword likely belonged to a civil official, since “it has both decorative and practical functions, but is not in the shape of [a] sword for military officers.” Recent dredging of the river may have brought the sword out of the silt and closer to the surface, according to the bureau official, who adds that archaeologists are now planning a larger dig there.

The boy’s dad admits that locals wanted to buy the sword from him for “high prices,” but he “felt it would be illegal to sell the cultural relic.” The bureau sent him and his inquisitive son a certificate and reward for finding the piece.