Aja is an African name for this type of sliced beads. The beads (and their name) came from the trade in Nigeria and Aja is probably a Hausa word.
Some are just sliced from drawn tubes in the cold state, but most go to additional labor. The thin slices are heated, squeezed and flattened with a tool in the hot state that give them a distinctive distorted look.
I believe they were made that way in Murano, at least the squashed version.
JP