Before the sixth century B.C. Chinese Coins were cast in the shapes of miniature shells, spades, and knives. These objects had been the principal items of barter in China prior to the minting of Coins.
Shell money was the oldest form of currency in ancient China. As the shells were small and hard in texture, they came in handy as money. By the Shang and Zhou dynasties the use of shell money reached its zenith, and shell money became a symbol of wealth.