This Cross is of solid gold and is set in the middle with a red cabochon stone to signify the blood of Christ. The top is mounted with the original gold loop for suspension.
Such gold Crosses typically are associated with the Byzantium period, and this example is likely to have its origins in the Eastern Mediterranean.
It is based on the basic pointed cross format but additionally is almost of avellan form. It has a central rectangular box and the arms have baluster-form detail which end in pointy finials.
The red stone, probably a garnet, is mounted in a gold box setting.
Cormack, R. & M. Vassilaki, Byzantium 330-1453, Royal Academy of Arts, 2008.