Rome began to develop its own monetary system relatively late. From about 289 BC minted silver and bronze coins were issued, as well as cast heavy bronze coins. The cast coins had marks of value to indicate the various denominations. The base unit was the as with an I as mark of value. 1 as was divided into 12 unicae.This coin is 1 uncia. It shows a pellet to indicate the value on both sides. The obverse additionally depicts a tiny bone; it is an astragalus, a talus bone. The Romans used such little bones for oracles.