In Australia, games were played with marbles of different sizes. The smallest and most common was about in diameter. The two larger, more valuable sizes were referred to as "semi-bowlers" and "tom-bowlers", being about and in diameter respectively. They were used in much the same way as ordinary marbles, although sometimes they would be declared invalid because of the advantage of their larger mass and inertia. Owners of large marbles were also afraid to use them because they could be lost to another player as "keepsies". They were usually of the clear "cat's eye" or milk glass type, just bigger.