These are "Scintillare" Beads, which in Italian means to sparkle, to glitter; and that is definitely true.
These handmade Venetian Glass Beads are made with a special process, and each bead glitters on the outside.
Sparkle Beads/Scintillare

Scintillare 20mm Round
$6.99

Scintillare 20mm Tubes
$4.98