Sestertius

The first Roman Sestertius (plural sestertii) was a small silver coin struck during the Roman Republic that weighed about 1 gram, or 1/4th the weight of the denarius. Under Augustan reforms, an orichaclum sesterius was introduced that weighed roughly 27 grams and measured about 33mm in diameter. Sestertii were struck almost continually until the late 3rd Century AD, with double sestertii being struck by Trajan Decius and Postumus. Sestertii were valued at 4 to the denarius. There large size provided ample room for some of the finest die engravers to create masterful portraits and designs. Some of the best Roman numismatic artwork can be found on sesterii, and until recently, a sestertius of Hadrian held the record for the most expensive ancient coin sold at auction. Sesterii are actively collected for both their artistic merit and their historically interesting reverse types.