Elephant and mammoth tusk ivory

Elephant and mammoth tusk ivory comes from the two modified upper incisors of extant and extinct members of the same order (Proboscidea). African and Asian elephants are both extant. Mammoths have been extinct for 10,000 years. Because of the geographical range in Alaska and Siberia, Mammuthus primigenus tusks have been well preserved. Therefore, Mammuthus primigenus is the only extinct proboscidan which consistently provides high quality, carvable ivory.

Polished cross-sections of elephant and mammoth ivory dentine display uniquely characteristic Schreger lines. Schreger lines are commonly referred to as cross-hatchings, engine turnings, or stacked chevrons.

Hippo ivory

Upper and lower canine and incisors are the most common sources for hippo ivory. Each type of tooth has distinctive gross morphology. Close examination of a cross-section of hippo dentine with the aid of a 10X hand lens reveals a tightly packed series of fine concentric lines. These lines can be regularly or irregularly spaced. The orientation of the lines will follow the overall shape of the particular tooth.

Bone

Bone is a mineralized connective tissue consisting of dahllite, proteins and lipids. Compact bone, which is most often used as an ivory substitute, is extensively permeated by a series of canals through which fluid flows. This is the Haversian System. The Haversian canals can be seen on a polished bone surface using a 10X hand lens. These canals appear as pits or scratch like irregularities. Their appearance is often accentuated by the presence of discolored organic material which adheres to the pit walls.

U.S. Fish and Wildlife Service