Hi Zam,
Meshorer speculates a little about the relative values of the
Antigonus coins, stating that the larger coin with the double
cornucopia represents double the value of the smaller coin with a single
cornucopia. The following is taken from Treasury of
Jewish Coins:
"The smallest monetary unit at the end of the Hellenistic period was the lepton, a small bronze coin. The value of a
good Hasmonean prutah (in contrast to the underweight ones of
Jannaeus) was that of a dilepton. The
drachm, a silver coin unit in circulation in the first century B.C.E., whose
weight was approximately 3.5g. of pure silver, served as the basis for evaluating the
denominations. The
drachm was divided into six small units, obols, which at that time were merely units for reckoning. Each
obol was divided into eight large bronze coins termed chalkoi (i.e., "copper" coins). Each chalkos was divided into seven leptons. Thus the
drachm contained 336 leptons or 168 prutot. There were 672 (4x168) prutot in a Tyrian
shekel.
According to the
weight relationship between the three bronze coin
denominations of
Mattathias Antigonus, it can perhaps be suggested that the large coin was a chalkos (1/48 of a
drachm), the medium one was a half-chalkos (1/96 of a
drachm), and the
prutah was, as mentioned, 2/7 of a chalkos. However, this is only an assumption and is possibly incorrect due to the lack of data. The large coins of
Mattathias Antigonus perhaps represent much larger
denominations, because in the case of bronze coins, their
weight was not of fundamental significance (even then bronze was of only symbolic value)."
Hope this helps!
Dave