A Pebble

1. A small stone, especially one rounded by the action of water.
2. (geology) A particle from 4 to 64 mm in diameter, following the Wentworth scale.
3. (curling) A small droplet of water intentionally sprayed on the ice that cause irregularities on the surface.
4. Transparent and colourless rock crystal.
5. A form of slow-burning gunpowder in large cubical grains.Synonyms: cube powder, prismatic powder