Billiard balls

I'm awfully glad they realized elephants were endangered and stopped killing them to make billard balls. From: Nice News And did you know... Early billiard balls were made of various materials, including wood and clay. Although affordable ox-bone balls were in common use in Europe, elephant ivory was favored from at least 1627 until the early 20th century. By the mid-19th century, elephants were being slaughtered for their ivory at an alarming rate, just to keep up with the demand for high-end billiard balls. The billiard industry realized that the supply of elephants was endangered, as well as dangerous to obtain. Inventors were challenged to come up with an alternative material that could be manufactured. John Wesley Hyatt patented an "ivory imitation" composite made of nitrocellulose, camphor, and ground cattle bone on May 4, 1869. The material was a success and was sold as Bonzoline, Crystalate, and Ivorylene until the 1960s. The ivory substitute was one of the most significant early reinforced plastics and induced the global growth of billiards, pools, and snooker. Source: Wikipedia