The short answer it is sort of but, not really,
rare.
There are a huge variety of enameled
Roman fibula. They are generally divided into bow and plate. Yours is a
bow fibula. They have a small plate with enamel on them.
Plate fibula consist of only a flat plate.
Enameled bow fibula are divided based primarily on two things - the shape of the plate with the enamel and the shape of the foot.
So yours is an
enameled bow fibula with round plate and fantail foot. It is know as
Exner type I/38 after Kurt Exner's
catalogue Die provincialromischen Emailfibeln der Rheinlande.
Exner's
catalogue lists two finds for
type I/38 - Trier and Zugmantel (near Mainz). Both are on the middle Rhine so perhaps yours was originally an import from there.
Yours is also very similar to
Exner I/37, which is the same shape, but with some enamel on the foot as well as the plate. He lists a find from Bonn - so same
area.
The actual enamel pattern varies tremendously. Exner's examples don't look like yours - one consists of concentric circles, the other of pinwheel design.
What this means is that your exact
fibula style - that is the exact mix of size, disc shape, foot shape and enamel shape and color is unlikely to be found in many others. But
enameled bow fibulae with round plates are not
rare.
SC
PS Not sure what "the book" is. There are literally tens of thousands of
types of
fibulae and hundreds of books about them.
