FOURRÉES, CAST, ANCIENT/MODERN COPIES & ?  FORGERIES.

Fourrées:

Counterfeits made for profit, during the time of Julia Domna, with the intention to deceive, usually imitate silver denarii, with pieces of a much less intrinsic value. These coins are often called `fourrées'. They are silver-plated coins, struck on flans, with base metal cores, thought to have been usually engraved by forgers. The effect is to produce coins which will pass for normal quality silver coins. The profit was in the substitution of cheap copper (the core) for expensive silver. You will often see the copper of the core, in places where the silver-plating has broken off and in many case no silver-plating remains at all.

The following coins compare Julia Domna's denarii with those produced by ancient forgers (?), some with silver plating remaining and others surviving as copper coins only.

"Limes":

Some coins were struck from dies that appear to be of an incorrect style. Sometimes called coins of the "limes". It seems likely that they were "a money of necessity", produced to support commerce on the borders ("limes"), where losses of precious metal to barbarian raiders was very likely. Whether this was approved or executed by the Roman authorities, or was purely a local matter, is not known.

Cast imitations:

Most casts are in a base grey metal. They do not have more depth of field than the coins they were cast from and they do often lose details in the process. Fourrées were often as bold as the originals.

Modern copies/Reproductions: 

Irregular Fourrées (hybrid):

These fourrées appear to be "irregular", as they have Julia Domna obverses linked with reverses apparently only minted  on coins of her husband, Septimus Severus.