I forgot to answer to you: I bought these beads in Cameroun, but, in Africa, it's very hard to know of where they come because the merchants are traveling a lot between the countries.
For example: I had a merchant who brought me many beautiful beads: he was a malian, he travelled all over the world like in a garden!! I phoned to me from Singapour, Munich, Tokyo, Bangkok, Lagos where he bought beads and any sorts of goods and he supplied the markets of all the African West. He also went in Afghanistan, Pakistan and he found gorgeous islamic beads!!!!!