Hippopotamus tusk is one of the most underrated materials in the world of worry beads, and among the hardest of all tooth materials. The hippo carries large canines in its lower jaw with exceptionally dense, fine-grained dentine and a thin layer of enamel; it is this hardness that yields a particularly smooth, almost glassy polish and a remarkably clean white tone, prized for yellowing far more slowly than elephant ivory. On the law, precisely: the hippopotamus is listed in CITES Appendix II, meaning international trade in its tusks is possible but only with permits and certificates; a responsible seller works solely with legally documented material, and a buyer should ask for the paperwork. In cross-section hippo tusk shows a fine concentric pattern and a dense texture free of visible pores. In the hand the material is noticeably dense, cool, heavier than its size suggests, with a smoothness that invites the fingers. Spun, it sounds bright and clear — higher and crisper than mammoth, with a faint crystalline edge from the high density. Patina builds slowly and delicately, a warm cream tone. Care is simple: stable humidity, no direct heat, a dry soft wipe. These beads suit those seeking purity of white, exceptional hardness, and a ringing voice — lovers of rare materials with an honest, lawfully documented pedigree.