There are other
Forvm threads or contributions relevant to these questions, but they may not be easy to find.
Reverse types are often equated with
officinae because when
officinae were first marked, in the final two issues of
Philip I and family, each
officina had its own
reverse type. So
officina I = A
had the
type Lion, then in the next issue TR P V
Mars;
officina II = B
had She-wolf and twins, then
TRANQVILLITAS AVGG; and so on.
So it's tempting to suppose that each
rev. type was produced by its own workshop at the
mint, with each workshop perhaps even having its own engravers. This theory is pretty much destroyed, however, by
Colin Kraay's recognition that
overstruck rev. dies mean that two
rev. dies were being employed alternately with the same
obverse die. Those
overstruck rev. dies were often of different
types; so each
reverse type was not being struck separately in its own workshop!
Rev. dies of different
types were often being struck alternately at one and the same
obv. die.
The important thing to establish is which
rev. types were being struck simultaneously in the same issue, what the relative production volumes of those
types were, and finally the correct order and approximate absolute dates of the different issues. Exactly how the
mint arranged its production of these coins is largely unknowable, and of very minor importance anyway. To answer economic and historical questions, we just need to know in what order and in what volume and approximately when the various
types were produced.
Robert Carson's "cyclical" theory of coin production, namely that the different metals and
denominations were produced one after the other in the same workshops, cannot be correct. There are many very
rare coin
types or varieties, which obviously cannot have remained in production more than a week or maybe a month, so on Carson's theory should only appear on one
denomination, or possibly two
denominations if the hypothetical switch between them happened to fall in the course of the week or weeks in question. But such
rare varieties regularly appear on three or more
denominations. For example the very
rare coins of
Julia Mamaea spelling her name IVLIA MAMIAS AVG or
AVGVSTA:
sestertii,
dupondii, and
denarii are known, and it will not be surprising if an
aureus too someday turns up. Such
rare issues, known in multiple
denominations, prove that the
mint was perfectly capable of producing all three metals, and all
denominations, at one and the same time. It is obvious that the production of gold and silver coins on the one hand, and bronze coins on the other, was each largely continuous and simultaneous with one another; there was no alternation of production between precious and base metals as
Carson supposed.
A "phase" of an issue is a
part which can be chronologically marked off by some change. For example Mamaea's MAMIAS coins could be called the "first phase" of her first issue. Or if you desire, you could call the MAMIAS coins Issue 1, and the
MAMAEA coins with the same
IVNO CONSERVATRIX rev. type Issue 2. That would produce difficulties, however: a very small Issue 1, and no way of marking off which of the contemporaneous coins of
Severus Alexander belonged to Issue 1 and which to Issue 2.
