Even before he started forward, Riddick had picked the cup up again — and slammed it down. Hard and sideways, at a carefully precalculated angle. The rock it scraped was jagged and broken. It imparted a similar edge to the rim of the cup. A serrated edge, though not one that would win any prizes at a tool-sharpening competition.
	It didn’t have to. The result was not neat, but it was effective. As the big guard reached him, Riddick blocked the slicing knife strike. Instead of retreating, he lunged ahead, right into his attacker. His right hand jammed the jagged rim of the cup forward, driving it in and down with tremendous velocity. The metal was thin but well-forged and composed of a particularly tough alloy, designed to take a good deal of rough treatment and last. Despite the force behind it, it did not snap and break.
	The muscles of the guard’s belly were composed of less sturdy stuff. The ragged edge of the cup rim ripped through them, making a very impressive hole. When Riddick drew his arm back, the hole filled with blood and bits of some slick, colorful internal organs. Stunned, the guard grabbed at himself. Riddick threw him back into his comrades.
-The Chronicles of Riddick (pages 203-204)