Hi all; I bought recently a multistrand necklace from Ethiopia, possibly mid XX century. I got it because of the black and white cylindric beads clearly recognizable as Venetian; the red beads are Cornaline d'Aleppo, possibly (?) Venetian too. There is a terminal row of green round beads, diameter about 7.5 mm, of a type I'm not familiar with: they have a seam in the sense of the perforation, as if they were made from two glass hemispheres. Any idea about their origin?