Ivory
Ivory is a yellowish, elastic, moderately hard dentine of continuously growing teeth (tusks) of mammals such as both recent and fossil elephant, walrus, hippopotamus, sperm whale, narwhal and some species of ungulates such as wild boar and warthog. Ivory consists of 25% organic material and water, and 75% inorganic apatite.
Ivory has been used as a biological gem material for many thousands of years.
Ivory has been used as a biological gem material for many thousands of years.
| Ivory Treatments | |
|---|---|
| Heated or dyed with tea to darken the color - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | |
| Ivory Simulants | |
| Ivory has been imitated by many look-alike materials that include glass, plastic, bone and vegetable ivory. - Michael O’Donoghue, Gems, Sixth edition, 2006, p.665 | |
| Physical Properties of Ivory | |
| Mohs Hardness | 2 to 3, Gemmological Tables (2004) More from other references |
| Specific Gravity | 1.70 to 2.00, Blue Chart Gem Identification (2010) More from other references |
| Cleavage Quality | None, Gemstones of the world (2001) |
| Optical Properties of Ivory | |
| Refractive Index | 1.535 to 1.570, Gemstones of the world (2001) More from other references |
| Birefringence | None, Gemstones of the world (2001) |
| Pleochroism | None, Gemstones of the world (2001) |
| Dispersion | None, Gemstones of the world (2001) |
| Colour | |
| Colour (General) | White, creamy, Gemstones of the world (2001) More from other references |
| Transparency | Translucent,Opaque, Gemstones of the world (2001) More from other references |
| Fluorescence & other light emissions | |
| Fluorescence (General) | Most ivory: bluish white to violet blue (SW weaker), Blue Chart Gem Identification (2010) |
| Fluorescence (Long-Wave UV) | Violet-blue, Gemmological Tables (2004) |
| Crystallography of Ivory | |
| Crystal System | Amorphous, Blue Chart Gem Identification (2010) |
| Further Information | |
| Mineral information: | Ivory information at mindat.org |