Its principal unit is called "stater" and in Attic
standard, it was Didrachm weighing 8.6g, though it was changed
to Tetradrachm weighing17.2g. This standard was also adopted
not only in some cities of Sicily, northern part of Aegean islands,
but also in Macedonian kingdom since the reign of Alexander
the Grate.
Corinthian Stater was also 8.6g, though it was not Didrachm,
but Tridrachm, so the drachm weighing 2.9g. This standard was
adopted in the cities of north-west Greece, many colonies in
Italy and Sicily.
Aigina, who introduced the coinage earlier than any other Greek
mainland cities, had also her own standard. The stater was Didrachm
weighing12.6g so the drachm was 6.3g. This standard was adopted
in the cities of Peloponnese, central Greece, Cyclades islands,
Crete and Southern part of Asia Minor.
Some Euboean cities also had another standard. The stater was
Tridrachm of16.8g and the standard was adopted in Euboean colonies
in northern Aegean islands and Sicily.
Sicily after the middle of 5th century produced many bronze
coins and the standard was differed from the silver coins, which
had same standard as Greek cities. The standard is called "Litra"
and though the weight was differed from the cities, Litra was
always divided into 12 "Onkiai". Other than these
unit, there were Hemilitron (=6 Onkiai), Pentonkion (=5 Onkiai),
Tetras (=4 Onkiai), Trias (=3 Onkiai) and Hexas (=2 Onkiai).