Shell money most valued by the Native American tribes of the Pacific Coast from Alaska to northwest California was "Dentalium shell", a species of long narrow marine shelled mollusk, a tusk shell or scaphopod. The tusk shell is naturally open at both ends, and can easily be strung on a thread. This shell money was valued by its length rather than the exact number of shells; the "ligua", the highest denomination in their currency, was a length of about 6 inches. Farther south, in central California and southern California, the shell of the olive snail "Olivella biplicata" was used to make beads
Kiffa beads 1980s. According to Peter Francis, Jr., the making of powder glass beads in West Africa may date back a few hundred years, and to possibly 1200 CE in Mauritania. Maure powder glass beads are believed to copy older, Islamic beads, of the type made in Fustat and elsewhere. Although the making of Mauritanian powder glass beads appears to be an ancient tradition, no archaeological evidence to establish their age has been found to date. Glass which is finely crushed to a powder is mixed with a binder such as saliva or gum arabic diluted in water. Decorations are made from