"We begun noticing discrepancies as we ended up building the database," examine lead author Jack Baker, a doctoral student of prehistory within the College of Bordeaux in France, advised The powerful hardness and brittleness from the materials manufactured it not possible to wear, grind, and bore the shell by equipment https://medium.com/@spoilmevintagediy/the-rich-history-of-beadwork-a-journey-through-the-ages-4e4fd2e474cf