Imperial Byzantine Glass Weight (6-7 century CE)

A four keratia “Imperial” glass weight of the Byzantine Period (17mm in diameter, weighing 0.62g), used  for weighing gold coins. The obverse depicts a haloed Imperial bust above a cross-shaped monogram flanked by two smaller busts. The monogram reads EVΘAΛIOV (‘of Euthalios’ in Greek). This is the only example known of a four-keration denomination glass weight. Others weighing either a nomisma (24 keratia), a semissis (12 keratia) or a tremissis (8 keratia).

Weights of this type have been described as ‘Imperial’ due to the presence of one or more imperial busts. The name Euthalius apparently refers to a high-ranking Byzantine official under whose authority the weights were manufactured.