Murano Pavone Glass Necklace

This pretty Venetian Murano glass lentil bead ( a round bead which has been partially flattened) measures 18mm (1.8cm or almost 3/4") 
 
It features interior Sterling silver foil and a filigrana pattern in black and white glass along with ribbons of aventurina (copper)  It comes on an 18" Sterling silver chain