Coins were invented around 600 B.C. The foremost and most popular denomination of Roman coins was the silver denarius, first issued in the late third century B.C. and removed from circulation in the A.D. 200's. The earliest denarius weighed 4.5 grams of high-grade silver, showing the head of Roma and the numeral X. Denarii, together with other silver, bronze and occasional gold pieces, were made at many mints.

Apart from Rome, there were two mints in Sicily, one in Sardinia, one in southeast Italy and probably others that have not yet been identified.

Denarius coins are surviving witnesses to an Empire that stretched across most of Europe, Asia Minor and Northern Africa. Before Great Britain's currency shifted to the decimal system in 1971, the British penny was abbreviated as "d", for denarius. The denarius is also the penny referred to in the New Testament.

Coin minting techniques involved using a heavy hammer to strike coin blanks between two dies. Like squeezing clay between your fingers, the pressure often caused the blank to elongate or even split at the edges, therefore making it impossible to produce a perfect spherical shape.

Web sites to visit for additional information on the historical Denarius coin:

Roman Imperial Coin Denominations
Roman Coins