History
According to the 1998 book Marbles: 101 Ways to Play, marbles originated in Ancient Rome and Egypt. The small spherical toys were named after the Latin word for "expensive stone."
Features
Modern marbles are usually not made from the actual marble rock. Factories produce marbles by dropping hot glass in steel rollers designed to round out the toys and give them the spherical shape.
Size
Marbles come in multiple sizes. The standard small marble size is usually half an inch in diameter. Larger marbles, used as "shooters," are usually around ¾ inch in diameter when used for official play. However, other sizes are available.
Considerations
In order to shoot a marble professionally, a specific technique must be learned. A player places her knuckles on the ground. The shooter is then placed between the first and second finger with the forefinger curled around the marble. The player then flicks the marble.
Fun Fact
The National Marbles Tournament is held annually each June in Wildwood, New Jersey. Players are aged seven to 15 and play a game with marbles called "Ringer."