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 manufacture wampum and eventually the primary source of wampum was that manufactured by colonists, a market which the Dutch glutted. Wampum briefly became legal tender in North Carolina in 1710, but its use as common currency died out in New York by the early 18th century. William James Sidis wrote in his 1935 history; The weaving of wampum belts is a sort of writing by means of belts of colored beads, in which the various designs of beads denoted different ideas according to a definitely accepted system, which could be read by anyone acquainted with wampum language, irrespective of what