There are several similar finds of this type of marble on Gotland, the largest measuring 4,8 cm in diameter. It was found at Gustavs in Fröjel parish, hence the name.
These honed, silver-incased rock crystals were probably worn as ornaments, but can also be used as magnifying glasses. The marbles are unique to Gotland in the Nordic area and most likely the honed crystal was imported from Persia and later incased and finished on Gotland.
10th-11th century CE
Silver (925) and rock crystal
Diameter (the rock crystal): 16 mm
Height (the loop and ring included): 37 mm
Weight: 10 g