The study of coins is known as numismatics. It not only includes visual elements such as script and images on the coins but also metallurgical analysis. Ancient coins were mostly minted in metals such as copper, silver, gold and lead.
The earliest coins found in India contained certain symbols and were called punch-marked coins. They were made of silver and copper (sixth century BC onwards). The first coins to bear the names and images of rulers were issued by the Indo-Greeks, who established control over the northwestern part of the subcontinent (second century BC).
The first gold coins were issued by the Kushanas in first century AD. Some of the most spectacular gold coins were issued by the Gupta rulers. Their earliest issues are remarkable for their purity of gold content.
Coins provide useful information regarding economic history as they were used as a medium of exchange. Some coins were issued by guilds or associations of the merchants and craftsmen with the permission of the rulers. This shows the influence of craft and commerce. Coins also portray kings and gods, and contain religious symbols, all to which throw light on the art and religion of the time.