Probably dating to the 8th century, with 9th-century alterations, it is an intricately designed, silver-gilt dress fastener that is closely related to a select group of brooches that were produced in Ireland and Britain during the 'golden age' of late Celtic art.

[1] The brooch and pin were cast in silver with exquisite geometric and zoomorphic interlace patterns and inset with three green-glass cabochon gems (one of which is missing).

Several moulded sections were used; although the main ring was cast in one piece, other goldsmith's techniques were used in the decoration.

[3] The pin, which moves freely around the ring between the terminals (see other picture), is broken but would have originally extended to at least double the brooch's diameter.

It appears to be a replacement, made in Scotland, probably at the same time that the form of the ring was adapted by cutting the bridge to make the brooch truly penannular.