AR Quinarius (Billon Quinarius)

"AR" is an abbreviation for the Latin word for silver, "Argentum".  "Quinarius" is a Latin adjective which means "containing five" and is used to describe the half of the silver denarius.  The "AR" is necessary because although the name "quinarius" only applied to the silver half of the denarius, common Roman usage extended the term to the half of the so-called "golden denarius", or aureus (the half being the "Au quinarius"). The denarius, first issued about 211 BC during the Second Punic War, originally was equal to 10 asses (see As) and bore the mark "X" to reflect its value.  Its half (originally issued at the same time as the denarius) was therefore worth five asses and thus called a "quinarius" and bore the mark "V" to reflect its value. Throughout its life the weight of the quinarius, as a fractional piece, followed the weight of the denarius.

The first silver quinarii were issued at about 2 scruples, or 1/12 of a Roman "uncia", or ounce of 98% fine silver. Since there were 12 unciae to the Roman "libra" (pound), this meant that the quinarius was struck at 144 to the pound, or 2.27 grams. However for an unknown reason quinarii ceased to be struck after about 170 BC until the "lex Clodia" of about 100 BC.  Mintage resumed after 100 BC, but at a reduced weight of about 2.27 grams, reflecting the weight reduction the denarius had undergone about 150 BC. The mark of value "V" was not revived on the new issues (it was re-tariffed to 8 asses anyway about 141 BC).

Although under the late Republic the quinarius was not a particularly scarce coin, it became so under the Empire. The imperial quinarius weighed about 1.8 grams under Augustus, but the next emperor to strike the denomination was the traditionalist Galba (68-69), who struck it at about 1.7 grams. Not only was its weight reduced, but its fineness was reduced to about 82% to follow Nero's reform of the denarius of 64.  Beginning with Vitellius (69) virtually every emperor struck quinarii although they are extremely rare today.

The quinarius continued a slow downward drift in weight, reaching 1.6 grams by the reign of Trajan (98-117) and finally reaching about 1.57 grams before it virtually disappeared from the monetary system about 240. However, its weight was not as much of a problem for its survival as was its fineness. It drifted downward until by the reign of Marcus Aurelius (161-180) it was 75% fine. Unfortunately the debasement accelerated under the Severans to about 50% by 215 when Caracalla (198-217) introduced the "antoninianus". That denomination was probably tariffed at two denarii although it only weighed about 1.5 times as much as a denarius. Its creation was probably necessary since any serious further debasement of the denarius and quinarius would give them the appearance of mere billon. Therefore an avenue other than debasement was needed, and the new "ersatz" double was introduced.  Once again Gresham's law was perhaps unknowingly invoked, with the nearly-fatal result for the denarius and quinarius that they ceased to circulate, since two antoniniani were worth four denarii or eight quinarii, although containing only 75% of the silver.  However the denomination was retained in the monetary system until it was replaced by the "half-argenteus"of the Tetrarchy. It ceased to be "silver" by the end of the reign of Gallienus, and such small numbers as were struck were of a very base billion (about 4% silver; those of Diocletian (q.v.) being the most common).  Sometimes the late third-century quinarius is referred to as an "Ae quinarius", although there was no such denomination, the "Ae quinarius" simply being the nearly totally debased "Ar quinarius".  The "Ae quinarii" weighed about 1.75 grams.

Invariably under the Empire the obverse was either the bare or laureate bust of the emperor.  Its reverse was almost always a "Victory" motif for the first century and a half of the Empire, but afterward "Victory" ceased to dominate.  The diameter of the silver quinarius was relatively constant with time at between 14 and 16 millimeters.