Beautiful Cobalt Blue Dogon Donut Beads

Exceptionally nice strand of cobalt blue Dogon disc-donut shaped (annular) beads. They were originally made by the Dutch and were produced from approx 1840 until 1900. They are strung on cotton cord. The strand measures 33.5" long, each measuring approx 13-15mm in diameter. There are approx 225 beads in total.