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
Wampum with quartz drill bits and steatite weights were used to drill the shells. The unfinished beads would be strung together and rolled on a grinding stone with water and sand until they were smooth. The beads would be strung or woven on deer hide thongs, sinew, milkweed bast, or basswood fibers. The term "wampum" is a shortening of "wampumpeag", which is derived from the Massachusett or Narragansett word meaning "white strings of shell beads." The Proto-Algonquian reconstructed form is thought to be "*wa·p-a·py-aki", "white strings." In New York, wampum beads have been discovered dating before 1510. The introduction of European