The set was first unearthed accidentally by Nguyen Van Hoi’s family members in Yen Minh Town when they were preparing to build a house. 

The stone hoes, which were carved in quadrangle form and polished smoothly, were found next to one another with the traces of burnt coal nearby. 

Scientists confirmed that the tools measuring 18cm in length and 7cm in width and 2.5cm thick were made of hard riolit stone, which is abundant in the area. 

Based on their chipped edges, experts believe that they were tied to sticks serving as handles for quite a long time.