Diamond Glitch

The Diamond Glitch (also known as the Holding n' Talking glitch) is a glitch found in Luigi's Mansion. To do this glitch, the player must go into The Artist's Studio and capture the Boo inside the room. This should be the last boo you need to catch. If done correctly, Luigi will awarded a Gold Diamond. The player must suck up the whole Boo until the player captures him. Then, before E. Gadd calls Luigi, the player must grab the Gold Diamond at the same time you (Luigi) sucked up the Boo. If done correctly, Luigi should hold the diamond in his hand at the same he's talking to the professor. After Luigi finishes talking, he will show the diamond to the screen as if he just obtained it.

Trivia

 * Although it can be done with other diamonds, this glitch is easier since the Gold Diamond lasts longer than any other diamond.