When was the stone hammer invented?

the first stone tools were not invented by humans but by the chimps! they made stone tools resembling sharp knives or hammers but they could not give their tools a proper shape.

the first stone hammer invented by human beings was probably around 1.5 million or 2 million year ago- that is when man started hunting. they were made from stones as they were easily available and more tough. they made the tools by hitting one stone to another. they used usually basalt but sometimes chert or flint.