Tooth and tusk ivory can be carved into a vast variety of shapes and objects.
Walrus ivory has a primary dentin layer and a secondary dentine layer, with the secondary layer having a marbled appearance (MFMHS).
Plastics have been viewed by piano purists as an inferior ivory substitute on piano keys, although other recently developed materials more closely resemble the feel of real ivory.
Ivory was often used to form the white of the eyes of statues.
One imitation ivory is made from cellulose nitrate and another from casein (the phosphoprotein that accounts for nearly 80 percent of proteins in milk and cheese) (MFMHS).
Ivory can be taken from dead or live animals.
Due to the rapid decline in the populations of the animals that produce it, the importation and sale of ivory in many countries currently is banned or severely restricted.
Mammoth ivory is used today to make handcrafted knives and similar implements.
The ivory of various animals differ in many other ways (Springate 2000; MFMHS).
Many African countries including Zimbabwe, Namibia, and Botswana claim that ivory trade is necessary—both to stimulate their economies and reduce elephant populations that are considered to be harming the environment.
Trade in the ivory from the tusks of dead mammoths has occurred for 300 years and continues to be legal.
At the same time, the historical popularity of ivory has resulted in rapid declines of elephants and other animals taken for the ivory trade.
Under ultraviolet light, synthetics will fluoresce a dull blue, and natural ivory a bright blue (MFMHS).
Ivory was prized for containers due to its ability to keep an airtight seal.
A species of hard nut is gaining popularity as a replacement for ivory, although its size limits its usability.
Hippopotamus ivory has a thick enamel coating, is denser and harder to carve than elephant ivory, and has a finer grain; it is often used for flat items, such as buttons and inlays (Springate 2000).
Ivory was also commonly carved into elaborate seals utilized by officials to "sign" documents and decrees by stamping them with their unique official seal (Stiles 2003).
Before plastics were invented, ivory was important for cutlery handles, musical instruments, billiard balls, and many other items.
Both the Greek and Roman civilizations used large quantities of ivory to make high value works of art, precious religious objects, and decorative boxes for costly objects.
The importation and sale of ivory currently is banned or severely restricted in many countries.
A small example of modern carved ivory objects are small statuary, netsukes, jewelry, flatware handles, furniture inlays, and piano keys.
The Chinese have long valued ivory for both art and utilitarian objects.
Chinese craftsmen carved ivory to make everything from images of Buddhist and Taoist deities to opium pipe (Martin 2007).
The Indianized Buddhist cultures of Southeast Asia, including Myanmar (Burma), Thailand, Laos, and Cambodia traditionally harvested ivory from their domesticated elephants.
In 2002, the United Nations partially lifted the ban on ivory trade, allowing a few countries to export certain amounts of ivory.
The beauty, smoothness, ease of carving, adhesive hardness, and durability of ivory has made it attractive for many ornamental and practical uses.