The objects of value that have served as forms of currency, have gone through considerable change over the past 10,000 years.
We began with a barter system, where traded services and resources resulted in an agreed upon exchange of mutual advantage. In fact, individuals, organizations, and governments still prefer to use the barter system of exchange in some cases.
In 9000 – 6000 B.C with agricultural based communities, cattle and other livestock (sheep, camels, etc.) are the first and oldest forms of money. The use of grain and other vegetable or plant products became standard forms of barter in many cultures.
The first use of cowries, the shells of a mollusc, began in 1200 B.C. in China and were also used some time later in Africa lasting well into the middle of the last century. These shells were widely available in the Pacific and Indian Oceans shallow water areas. The cowrie is the most widely and longest used currency in history
China, at the end of the Stone Age in 1000 BC, began manufacturing the first and earliest forms of metal coins with Bronze and Copper cowrie imitations.
Coins outside of China were not made from inferior base metals as were the Chinese coins. The superior coins made in other countries at the time came from silver, bronze and gold. They first were made in Lydia, now present-day Turkey, and quickly copied by the Greek, Persian, Macedonian, and Roman empires. And later in China, 118 B.C., leather money was used.
Money Timeline from 800 A.D. to Present:
806: Paper Currency
1816: The Gold Standard
1930: End of the Gold Standard
The Future: Electronic Money
Source: PBS Article http://www.pbs.org/wgbh/nova/ancient/history-money.html