Editing Cue sports (section)

===Billiard balls===
{{Main|Billiard ball}}
[[File:Billiard ball comparison.jpg|thumb|{{Cuegloss|Cue ball|Cue balls}} from left to right: {{unordered list
| [[Russian pyramid|Russian pool]] and [[Kaisa (billiards)|kaisa]]—68&nbsp;mm ({{frac|2|11|16}}&nbsp;in)
| [[Carom billiards|Carom]]—61.5&nbsp;mm ({{frac|2|7|16}}&nbsp;in)
| American-style [[Pool (cue sports)|pool]]—57.15&nbsp;mm ({{frac|2|1|4}}&nbsp;in)
| [[Snooker]]—52.5&nbsp;mm ({{frac|2|1|16}}&nbsp;in)
| [[Blackball (pool)|Blackball]] pool—51&nbsp;mm (2&nbsp;in) 
}}]] <!-- I know you metric people try, but fractions aren't arbitrary; and do take into account significant figures in conversions. 2. Just 2. No "2 and 1/127", where the error is <.01, and even then 128 would be the appropriate denominator. -->
Billiard balls vary from game to game, in size, design and quantity.

[[Russian pyramid]] and [[Kaisa (billiards)|kaisa]] have a size of 68&nbsp;mm ({{frac|2|11|16}}&nbsp;in).  In Russian pyramid there are 16 balls, as in pool, but 15 are white and numbered, and the {{cuegloss|cue ball|cue ball}} is usually red.<ref>{{Cite web |url= http://www.billiardsvillage.com/russian-pyramid.html |title=Russian Billiards |publisher=BilliardsVillage.com |access-date=August 14, 2008 |date=2007 |url-status=usurped |archive-url= https://web.archive.org/web/20080613002125/http://www.billiardsvillage.com/russian-pyramid.html |archive-date=June 13, 2008}}</ref> In kaisa, five balls are used: the yellow {{Cuegloss|object ball|object ball}} (called the ''kaisa'' in Finnish), two red object balls, and the two white cue balls (usually differentiated by one cue ball having a dot or other marking on it and each of which serves as an object ball for the opponent).

Carom billiards balls are larger than pool balls, having a diameter of 61.5&nbsp;mm ({{frac|2|7|16}}&nbsp;in), and come as a set of two cue balls (one colored or marked) and an object ball (or two object balls in the case of the game [[Four-ball billiards|four-ball]]).

Standard pool balls are 57.15&nbsp;mm ({{frac|2|1|4}}&nbsp;in), are used in many pool games found throughout the world, come in sets of two {{Cuegloss|Suit|suits}} of object balls, seven {{Cuegloss|Solids|solids}} and seven {{Cuegloss|Stripes|stripes}}, an {{Cuegloss|8 ball|8 ball}} and a {{Cuegloss|Cue ball|cue ball}}; the balls are racked differently for different games (some of which do not use the entire ball set). Blackball (English-style eight-ball) sets are similar, but have unmarked {{Cuegloss|Group|groups}} of {{Cuegloss|Red ball|red}} and {{Cuegloss|Yellow ball|yellow}} balls instead of solids and stripes, known as "casino" style. They are used principally in Britain, Ireland, and some [[Commonwealth of Nations|Commonwealth]] countries, though not exclusively, since they are unsuited for playing nine-ball. The diameter varies but is typically slightly smaller than that of standard solids-and-stripes sets.

Snooker balls are smaller than American-style pool balls with a diameter of 52.5&nbsp;mm ({{frac|2|1|16}}&nbsp;in), and come in sets of 22 (15 reds, 6 "{{Cuegloss|Color balls|colours}}", and a cue ball). English billiard balls are the same size as snooker balls and come in sets of three balls (two cue balls and a red object ball). Other games, such as [[bumper pool]], have custom ball sets.

Billiard balls have been made from many different materials since the start of the game, including clay, [[bakelite]], [[celluloid]], [[crystallite]], [[ivory]], plastic, steel and wood. The dominant material from 1627 until the early 20th century was ivory. The search for a substitute for ivory use was not for environmental concerns, but based on economic motivation and fear of danger for elephant hunters. It was in part spurred on by a New York billiard table manufacturer who announced a prize of $10,000 for a substitute material. The first viable substitute was celluloid, invented by [[John Wesley Hyatt]] in 1868, but the material was volatile, sometimes exploding during manufacture, and was highly flammable.<ref name="IEOB">{{cite book |last=Shamos |first=Michael Ian |author-link=Michael Ian Shamos |date=1993 |title=The Illustrated Encyclopedia of Billiards |publisher=Lyons & Burford |location=New York City |isbn=1-55821-219-1 |url= https://archive.org/details/illustratedencyc0000sham }}</ref><ref>The New York Times Company (September 16, 1875). [https://select.nytimes.com/gst/abstract.html?res=FB0F1EFD345D1A7493C4A81782D85F418784F9 Explosive Teeth.] {{webarchive|url=https://web.archive.org/web/20140316033727/http://select.nytimes.com/gst/abstract.html?res=FB0F1EFD345D1A7493C4A81782D85F418784F9 |date=2014-03-16 }}. Retrieved January 2, 2007.</ref>