Mystery box

This glass and silver box was in my grandparents' house, and is at least 60 years old (it was there as long as I can remember). No one in the family knows what it is and what it was meant to be used for. It is etched crystal with silver inlays, separates into 2 pieces with semi-circles on either end of each piece to form a circular opening at each end when put together. Dimensions are 5" long, 1-1/2" deep and 3" high. Any information about what this might be would be welcomed.