Although not everybody agrees, generally the
Diocletianus
monetary reforms are classified in three and they refer to both a chronological
and metallic progression.
1.
Gold: Around 286 a new gold coin called “Aureo”
was introduced. This coin was minted 60 pieces to a Roman pound.
This meant a 12 grains increase in relation to previous gold coins
which were minted 70 to a pound.
2.
Silver: Although there is no certainty on the
name of the new silver coin which is generally called “Argenteus”,
it was issued with the same characteristics in silver content and
weight as the Denarius from
Nero’s
times. The Empire had been without silver coinage since the shared
government of
Valerianus and his son
Gallienus.
3.
Bronze: In 295 or 296 a new bronze coin called
Follis was placed into circulation. That coin had the weight approximately
like the Antoninianus. Including its silver wash. The post reforms
Antoniniani were not silver washed while the pre reforms had a 4%
silver in them, The XXI mark of the Antoniniani was transferred
to the Follis which has given enough arguments to consider that
the XXI mark really means the relation of 20 parts of bronze to
one of silver.
Another important change introduced by Diocletianus
was that the mint identifying marks started to appear regularly
on the coins.