One of the most widely used forms of money since ancient times has been the shell of the cowry. These beautiful shells of formerly living undersea creatures were independently chosen as a preferred form of money by numerous ancient cultures, many of which had no initial contact with each other, because of the cowry shell's desirable monetary properties. The shells fulfill many of the traits of an ideal form of money, as they are durable, easily counted and exchanged, and also very difficult to counterfeit.
In India, the shells functioned as a lower-denomination currency next to silver (while gold was reserved for large transactions). Cowries also became a well-favored form of money in China. To what exact extent they were used as money in the earliest mists of Chinese history is not well known today, but at the very least they were clearly valued as treasures at a very early date. The ancient Chinese character for "money" (bei) even features a stylized depiction of a cowry shell, adapted from earlier cowry depictions found on oracles bones and bronze inscriptions.
During the Zhou dynasty, evidence of the shells' buying power was noted, along with discoveries of cowries in common graves, as well as in the treasure troves of the wealthy. A notable example of the coining of imitation cowries took place in the Sung dynasty, in which the currency was known by the peculiar name of "Ant Nose money." By some accounts, this form of money was used in burial rites by being inserted into the noses of the dead, in order to keep out the ants— however, other sources insist that this was not done, and that the name was actually based exclusively on the shape of the Chinese characters. These cowry coins were also known as "Ghost Face money."
The imperial Chinese governments eventually standardized the metal money, and at one point cowry shell currencies were banned following the official issue of copper coins. However, after the government went on to debase the official coinage, the debased coins were themselves banned, and the cowry shell currencies were once again restored as a permissible form of legal tender.
Arabian traders plying African trade routes apparently found great profit by buying and re-selling cowries. By some accounts, Arab traders were able to buy one million cowry shells for a single gold dinar, and then resell the shells in Nigeria at an exchange rate of 1,000 shells per gold dinar.
The Arabian arbitrageurs correctly anticipated that the shell of this different genus of cowry would be accepted as a substitute for the more scarce and higher-valued money cowries— but by introducing huge amounts of new money into the economy, they caused inflation to spread across Africa. The same thing reportedly took place on an even larger scale in the 16th century, when various European traders shipped billions of cowry shells into West Africa.
By the mid-19th century these huge expansions of the cowry money supply had caused a major devaluation of the shells. In some cases the cowry money had become so plentiful and devalued that it had to be traded in large sacks, with huge amounts of time consumed by the need for counting hundreds of thousands of shells. The sudden introduction of huge amounts of new money into the economy had caused a drastic decline in the purchasing power of the money, as is commonly the case (unless major deflationary forces are present to counter the inflationary effects of monetary expansion).
Nonetheless, the beauty of the cowry shells and their long historic legacy as a prized form of international money still make them a valued possession, and a few rare places have even continued to recognize cowries as a legal form of currency in the modern era.