Known. People at Ile-Ife made glass beads from materials close to home.
At Ile-Ife, in south-west Nigeria, a dig found almost 13,000 coloured glass beads from about the 11th to the 15th century. There were also broken clay pots used to melt glass, clay with melted glass on it, and piles of glass waste. Many of the blue beads were made almost only from materials found near Igbo-Olokun. No furnaces were found, but the waste shows the workshops were there, or very near.
The page says more research is needed before anyone can say this bead method began here.