Three hundred years ago, wampum could buy enough land to start your own plantation. In fact, you could even use wampum to pay your taxes to the Commonwealth of Massachusetts and pay your tuition at Harvard College. Wampum is typically a cylindrical bead, not a disk bead, and much of its value comes from the work that goes into drilling pieces of shell lengthwise, which is far more difficult than drilling the short way through. Although polished pieces of quahog shell are often sold as wampum, but they're really not wampum unless they have been drilled as beads. For the record, white wampum was also made from the central colums of whelk shells, which are also found in New England.
Whelk is softer and easier to drill, but it is never purple.
Also, whelk columns are pre-formed into a cylinder shape. The whelk might be the secret to how the Native Peoples produced as much wampum as they did. In the world of gem materials, wampum, with its deep purple swirls blending into a white background, is in a class with pearls, precious coral, and amber. Another virtue is scarcity. Only a handful of crafters have mastered the art of making wampum and have the fortitude to produce it on a regular basis.