The selection of N. gibbosulus in Mediterranean web sites and N. kraussianus is South African web pages is actually a functionality of their availability while in the vicinity of the internet sites, but would not describe why this genus was chosen about other shells of comparable sizing and condition. A https://medium.com/@spoilmevintagediy/the-rich-history-of-beadwork-a-journey-through-the-ages-4e4fd2e474cf