Why Are Dominoes Called Bones?
Dominoes are called "bones" because the earliest domino tiles were made from animal bones or ivory. In addition to "bones", dominoes are also called "tiles", "stones", or "men".
Originally, dominoes were made from ivory inlaid of with ebony pips. Ivory dominoes are among the most sought-after and rarest domino sets. This is because the harvesting of ivory has resulted in the slaughter and near-extinction of elephants and other large mammals. The ivory ban was imposed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) after the number of African elephants declined by almost 50 percent in the 1980s. It is currently illegal to produce ivory dominoes, as well as other ivory products. However, it is legal to sell historical ivory domino sets produced before 1989, though there is no easy way to date most ivory, so it may be difficult to sell a vintage domino set without the proper documentation showing the history of the set.
So-called "vegetable ivory", made from the Tagua Nut, known as the "ivory nut", has been used for over two hundred years by craftsmen to make dice, dominoes, & chess pieces. The ivory nut is close-grained and very hard, and its structure, color, and grain is similar to that of mammal ivory, though it is slightly softer.
Some of the more collectible domino sets are made of "bois durci," a 19th-century version of plastic made of sawdust and egg whites. Later, dominoes were made from Bakelite, a form of plastic invented in 1907 and manufactured until the 1950s.
Today, dominoes are made from less-exotic materials such as wood, plastic, and even aluminum. There are also dominoes made from paper cardstock similar to playing cards.
Dominoes are generally either made of white material with black dots, or dark material with white dots. Some sets use color dots (one color per suit) to make it easier to make matches - just connect the colors.
There are even some dominoes which use numbers instead of dots, making it still-easier to make matches. Still other sets use pictures of objects, such as animals, flowers, or food instead of dots or numbers. These sets are especially popular with children.