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
Worry beads roll them against each other, creating soft clicking sounds. Worry beads can be a musical instrument, related to rebetiko. Sound is emitted using a drinking glass and rubbing the lip against the worry bead, which is suspended from one button. It is also superstition in certain Greek communities that husbands-to-be, on their wedding night, will perform a "worry bead ritual" involving rapid back-and-forth movement of all beads. This is meant to ensure sexual fulfilment (συνουσία, "synousía"), on the wedding night and during the following honeymoon period. Worry beads Worry beads or kombolói, kompoloi (, , "bead collection"; plural: , )