In "The Necklace," how does the symbolism of the necklace change from something positive to something negative as the story evolves?
In the beginning of the story, the necklace represents everything that Loisel doesn't have--wealth, elegance, praise, adoration, and luxury. When she sees the necklace for the first time, she has an immediate reaction:
"Her heart throbbed with an immoderate desire. Her hands trembled as she took it."
The glittering necklace symbolizes her glittering hopes and dreams, the fulfillment of all of her desires. As she dons the necklace and goes to the party, she finally feels like she is where she belongs. She is happier than she has ever been:
"She danced with rapture, with passion, intoxicated by pleasure, forgetting all in the triumph of her beauty, in the glory of her success, in a sort of cloud of happiness comprised of all this homage, admiration, these awakened desires and of that sense of triumph which is so sweet to woman's heart."
That necklace gave her the life that she had so craved, if even for one night. However, after the necklace is lost and she has to work for years, slaving to pay off the debt, the necklace comes to symbolize misery. It symbolizes the price that one must pay for greed, for materialism, and for setting ones hopes so entirely on being rich and admired. It represents the years of backbreaking labor that it took to pay off something so trivial as a necklace. Instead of the fulfillment of her dreams, it represents the destruction of her dreams. At the end of the story Mathilde is a ruined, work-weary, roughened character whose dreams of luxury and wealth are no longer even within dreaming grasp, and the necklace is the symbolic cause of that "fall". I hope that those thoughts helped; good luck!