It was intended to be worn as a pectoral crucifix, perhaps holding a fragment of the True Cross in the compartment inside.
The cross is thought to have been made in southern Italy around the end of Byzantine iconoclasm, between 843 and the mid tenth century.
It has a hinge at the top and catch at the bottom of the cross, so it can be opened to permit a small object to be placed in the cavity within.
The arms of the cross also bear faint Greek inscriptions, The other side of the cross shows the Virgin Mary, standing with hands raised in prayer, flanked by busts of the saints Peter and Andrew, as Mary and Joseph were on the other side, with busts of John the Baptist above and Paul below.
The medium is not good at rendering small detail and is more commonly used for geometric or vegetal subjects such as flowers, vines, or fruit, and not human forms.
The shade of translucent green enamel used as a body colour indicates a date between 843, when iconoclasm ended in Byzantium, to the mid tenth century.
His collection was sold by Alexander Beresford-Hope at Christie's in May 1886, when the cross was acquired for the Victoria and Albert Museum.