Call a spade a spade (or a coin)
Money in many people's minds will make them think of two things: dollars and cents, or bills and coins. When people seek to buy something, they use those bills and coins to equate to a certain amount of something valuable—five dollars, 20 dollars, or four dollars and 45 cents (the price of a tall Pumpkin Spice Latte, hello fall!). But what if that value was represented by something else, by something that looks like an everyday tool—like a phone, a pen, or a calculator? Ladies and gentlemen, I give you knife, spade, and bridge money!
The first instance of a currency in ancient China was the cowrie shell, most likely brought back from the Japanese seas and modern-day Hong Kong areas, during the Shang Dynasty (around 1766–1154 BCE). It was not until the Spring and Autumn period (around 771–476 BCE) that metallic pieces of currency began to be used regularly. Some of the largest and most prevalent metallic pieces were pieces of knife, spade, and bridge money. Knife, spade, and bridge money all have similar origin stories. These coins were derivative productions of agricultural tools (oddly enough knives, spades, and a musical instrument!) that would have been bartered with in ancient China. But notice numismatists and scholars call these "coins" or "money" rather than the tools they mimic.
A coin is a piece of metal that has been marked by an authority to denote its value, which is not necessarily the same as its base metallic value. Knife, spade, and bridge money are money rather than the tools they represent because they are 1) shaped metallic pieces and 2) marked by an authority to denote their value. The mark on spade and knife money typically describes either the location of production or the ruling authority, and as the currencies developed the text often became longer and more intricate. These would definitely not have been mixed up with the objects they mimic. Imagine gardening with a quarter, or worse, a 20 dollar coin!
Bridge money is slightly different than knife and spade money. These objects are most likely derived from jade charms akin to a Western musical triangle. Bridge money has many similarities to Chinese burial charms and amulets, making it a very distinct monetary piece. The markings on these objects do not often describe where they were produced or who produced them—as knife and spade money does. Instead, bridge money is very meticulously decorated, some even have the heads of dragons or phoenix!
As knife, spade, and bridge money continued to develop, they became more stylized, appearing less and less like the tool they represented. Late spade money got smaller and smaller, until it became close in size to contemporary coins!
These currencies were some of the first to appear in the world! They represent a unique step in the coinage of Asia between bartering and cash coins (around 210 BCE). The knife, spade, and bridge money even reappeared on Chinese currency during the 20th century. These 1 fen and ½ fen coins both depict an early spade coin as a marker of their value.
So as you go to order that pumpkin-spiced beverage tomorrow morning, imagine throwing your barista a spade, knife, even a dragon-head bridge coin!
Emily Pearce Seigerman is a museum specialist with the National Numismatic Collection.