Symbolism, Imagery, Allegory
When somebody has a piece of spinach stuck between his or her teeth, you can't help but stare. Minnie, the brothel maid, doesn't have something green stuck in her teeth: she has something gold—specifically, a gold tooth. And for all who are fortunate to see it, to really experience this tooth—well, they can't help but stare.
Minnie's gold tooth offers a bit of comic relief. Upon seeing the tooth for the first time, Lucius interrupts the story of how Ned traded the car for the horse by digressing and telling us about the tooth: "What I do remember," Lucius notes, "is the rich instantaneous glint of gold out of the middle of whatever Minnie said, in the electric light of the kitchen, as if the tooth itself had gained a new lustre" (6.1).
The tooth has a totally striking effect on Ned, too, for "it has stopped him cold for that moment, instant, like basilisk" (6.2).
Okay, so we know that the tooth is striking, but what's so special about it?
Well, like Lightning, it's also a prized possession that gets stolen. Otis sneaks into Minnie's room while she's sleeping, steals the tooth right out of her mouth, and hopes to sell it and make money. Though Otis is unsuccessful in selling the tooth, his attempts are just one more example of the selfishness and greed that Lucius encounters on his journey into adulthood.