Walrus ivory
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Walrus tusk ivory comes from two modified upper canines. The tusks of a Pacific walrus may attain a length of one meter. Walrus teeth are also commercially carved and traded. The average walrus tooth has a rounded, irregular peg shape and is approximately 5cm in length.
The tip of a walrus tusk has an enamel coating which is worn away during the animal's youth. Fine longitudinal cracks, which appear as radial cracks in cross-section, originate in the cementum and penetrate the dentine. These cracks can be seen throughout the length of the tusk. Whole cross-sections of walrus tusks are generally oval with widely spaced indentations. The dentine is composed of two types: primary dentine and secondary dentine (often called osteodentine). Primary dentine has a classical ivory appearance. Secondary dentine looks marble or oatmeal-like.