The hollow handled spade of the State of Zhou was one of the first use of real coins issued in China. This form of money is usually dated to about 700 BC to about 500 BC, but there are some arguments that might place them earlier. Around the 6th and 7th century BC, Zhou was the most powerful of several states and formed a central government that  exercised some control on the other states during the Spring and Autumn period. These states eventually became the Seven Warring States who fought each other during the Warring States period.

This early space money is amazingly thin usually measuring only about 1 or 2 mm in thickness, yet they are surprisingly strong and most survive intact and unbroken. This spade is marked with the character Gong on one side.