This rock crystal ring is particularly mysterious. It was found at Widdenberg near Mensdorf, at the site of a Gallo-Roman temple dedicated to the god Lenus Mars Veraudunus. It dates from the second century AD and depicts a high-relief female bust carved with great care and attention, particularly in the details of her hair. The band of the ring is incised with two intertwining lines.

Only a few rings of this type have been found anywhere in the Roman Empire. Rock crystal was a precious and sought-after material. It was also fragile and particularly difficult to carve.

Although these rings were sumptuous to wear, they were cumbersome and probably worn no more than occasionally. A fragment of a similar ring found in a temple at the Roman vicus of Dalheim shows that they were used for ritual purposes. Rock crystal, a pure and colourless quartz, was reputed to have magical properties.