Coinage metals

The coinage metals comprise, at a minimum, those metallic chemical elements which have historically been used as components in alloys used to mint coins. The term is not perfectly defined, however, since a number of metals have been used to make "demonstration coins" which have never been used to make monetized coins for any nation-state, but could be. Some of these elements would make excellent coins in theory (for example, zirconium), but their status as coin metals is not clear. In general, because of problems caused when coin metals are intrinsically valuable as commodities, there has been a trend in the 21st century toward use of coinage metals of only the least exotic and expensive types.

Historically, most coinage metals (or alloys) are from the three nonradioactive members of group 11 of the periodic table: copper, silver and gold, the copper usually being augmented with tin and often other metals to form bronze. Gold, silver and bronze or copper were the coinage metals of the ancient world, and most medieval coins.

All western histories of coins begin invention at some time slightly before or after 700 BC, in Aegina Island, or, according to others, in Ephesus, Lydia, 650 BC.Ancient India in circa 6th century BC, was one of the earliest issuers of coins in the world.

Since that time, coins have been the most universal embodiment of money. These first coins were made of electrum, a naturally occurring pale yellow mixture of gold and silver that was further alloyed with silver and copper.

However, the Persian daric was the first gold coin which, along with a similar silver coin, the siglos, (From Ancient Greek σίγλος, Hebrew שֶׁקֶל (shékel))represented the bimetallic monetary standard of the Achaemenid Persian Empire which has continued till today.Also, the Persian coins were very well known in the Persian and Sassanids era. Most notably, in Susa and in Ctesiphon.

...
Wikipedia