Ivory as an important model bio-composite

Vollrath F, Mi R, Shah DU

Elephant ivory has a long history as a highly valued commodity in many cultures because of its unique physical, chemical and mechanical properties that served both human wants and needs. Importantly, ivory allowed for aesthetic expression not possible historically with other materials: it carves well and lasts long even under heavy usage. And as such it has, over millennia, made its way into high-value ornaments, weaponry and household objects as well as false teeth and hip-replacements. Outside the human world, in the wild, for the animal, exceptional toughness is required of the elephant’s ivory when a tusk is being used to leverage trees to breaking point or act as a weapon in fights between bulls the size and weight of trucks. Little wonder that ivory has evolved properties and qualities so desired by ancient designers, artists, carvers and medics as well as modern pianists, pool players and, tragically, as ostentatious displays of wealth.


But this very nature of ivory is endangering the life and future of its key source, the elephant. This menace posed by human greed does, as it must, restrict, limit and prohibit the continued use of natural ivory. While modern composite materials have largely displaced the functional need for ivory, most of them lack its intriguing properties. Elephant ivory (which is the most important ivory traded even now) is a dense, multifaceted bone-like material of rather complex 3-dimensional construction and levels of porosity. Museum curators and antiquarians care about these properties of ivory for two reasons: regarding its historical value as material (in the sense of workable substance) and concerning its requirements for preservation and display.