Rock

Rock is a naturally-occurring solid substance composed of minerals.

Commander William Riker asked for rocks to be thrown at the following the USS Enterprise (NCC-1701-D)'s disabling by the Iconian probe which prompted a smile out of Ensign. 

The preindustrial civilization of Barkon IV incorrectly believed that rock was one of the four basic elements of the universe, along with fire, sky and water. Rock was believed to be found in everything in existence, and could be felt in an object's weight and hardness. 

Jadzia Dax once told Major Kira that she was a champion window breaker and that she was deadly on a dark night with a few rocks. 

Types of rock

 * Anthracite
 * Chalk
 * Igneous rock