The arms of this cross are fragments of Libyan Desert Glass, with their natural shape and surface fully preserved. This rare material is found in the Great Sand Sea, an expanse of the eastern Sahara straddling Libya and Egypt, where shifting dunes occasionally uncover specimens. Scientific dating places its formation at around 29 million years ago. Its mineralogical composition is that of desert sand fused into glass under the extreme heat of a major meteorite impact—although no suitable crater has ever been identified in the region. Throughout history, Libyan Desert Glass has been used by humankind, from knapped hand axes and arrowheads during the Ice Age to engraved scarabs in the jewelry of the pharaohs. In this cross, the glass arms are capped with yellow gold and meet at the center, where four rose-cut diamonds are set upon an engraved starfish-like ornament. On the reverse, the arms are joined by a lattice-like ornament, composed of diamond-set twigs of white gold. one of a kind