Jackstone

from The Collaborative International Dictionary of English v.0.48

Jackstone \Jack"stone`\, n.
   1. One of the pebbles or pieces used in the game of
      jackstones.
      [1913 Webster]

   2. (pl.) A game played with five small stones or pieces of
      metal. See 6th {Chuck}. Also called {jacks}. See
      {jack}[12], n.
      [1913 Webster]