Walters Art Museum:
This rare and beautiful crosier represents the only known example made entirely of rock crystal, a hard stone that is very difficult to work. The skill of the carver can be seen in the smoothly arching leaves and the series of small hooks, called crockets, lining the outer edge. An abbess may have used a crystal crosier as a sign of her purity, a symbolic interpretation that dates back to the 9th century.