I always enjoyed making “treasure necklaces” with interesting bits of things. This one is a long string of tiny “whiteheart” trade beads with a silver wire pendant.
The pendant is composed of a big yellow Venetian glass bead with blue ribbons, from which dangle items originating on different continents. At the top is a rough opal from Australia. In the middle are two more whitehearts and a small round agate from Brazil. On the left are three thin slices of fossil walrus tooth from Alaska. At the bottom hangs a talhakimt amulet pendant from Africa.
Talhakimt are distinctive of the Tuareg and Berber peoples in Niger, Mali and Algeria. Some are manufactured by them, but large numbers of these arrow-shaped ring pendants came from the stone-cutters of India and Germany. Later, Czech glassmakers produced inexpensive copies for the trade.
For more on amulets, see this page at the Pitt Rivers Museum in Oxford.