Read about it here!:
The coin is a gold solidus struck in imitation of a coin of Emperor Maurice’s reign (582-602). It is ‘rare’, as the article states, but also there is enough evidence to suggest that the minting of imitation gold coins was a relatively common practice in the Frankish kingdoms up until the late sixth century. This coin is probably one of the latest, therefore, made just as economic patterns East and West were diverging enough to minimise the value of widespread imitation. (Things were not all rosy and interconnected before the Arab conquests, if anyone was wondering having read Emmet Smith’s Mohammad and Charlemagne Revisited).
Adrian Marsden from Norwich Castle Museum is quoted as saying that it is hard to say how many of these coins would have been “official currency”. Indeed, Michael Hendy (Viator, 1988) and Ildar Garipzanov have argued that gold coins had a primarily fiscal purpose (they were connected with collecting taxes) rather than a market purpose (i.e. for trade).
That the coin has been turned into a pendant underlines the symbolic – or decorative – value the gold object obtained beyond its monetary value.