Lex watched Doom, and his expression grew serious. "Quite different. There are many different varieties of Kryponite. Some rarer than others, some more deadly than others. The green emits a kind of dead radiation to Kryptonians. The red ..." he trailed off, and glanced down at the apparatus in his hand.
"I'm sure that from time to time you've experienced rage." A finger flicked against the metal surface, before more pressure was applied by tapping against it forcibly. "An anger that takes over every thought, and quiets the rational side. Everyone has those moments, of course." Another even more forceful tap against the table. "Now imagine that you could have that anger switched on without provocation." A loud noise as the instrument was slammed repeatedly into the table. "Unhinged, unchecked, instantaneous rage. That is what this particular flavor of Kryptonite does."
Lex inspected the instrument in his hand once more, turning it over for close scrutiny. "Not a scratch. Good."