This is a photograph of a kiln inside which ground glass is being heated in molds to make glass beads. The place in question is the Cedi Bead making Factory in Ghana, West Africa. Glass is ground to a powder and sorted into different colours. The glass powder is then added to the bead molds in layers and other clever shapes in order to create layers of colour and then it’s fused in the heat of the kiln for an hour or so, which when cooled come out as beads.
It’s an ancient process that has been used prior to European colonisation, although nowadays crushed glass bottles of different colours are used.