A supplier who brings excavated beads from the Djenné region of Mali had a few strands of what look to me like German donut beads, except they are thicker and much rougher, showing every sign of having been buried and cleaned in the usual manner of the Africa trade. So, I wonder, are the "usual" thin donut beads in cobalt blue, green, amber etc, really German beads? Dubin's timeline shows them at the end of the 19th c. Are these excavated beads an early version of these, or something else entirely? My impression was that excavated beads from this region predate European sea trade, so did German beads get to Africa earlier than the Murano beads?