"The necklace" is a story by Guy de Maupassant, published in 1884. It tells the story of Mathilde Loisel, a woman who was beautiful on the outside, but unhappy on the inside. Mme. Loisel was consumed with her desire to have more status than she did. When she gets invited to an elegant party, she borrows a diamond necklace from her friend Mme. Forestier, only to lose it. Mme. Loisel and her husband spend the next ten years trying to pay the replacement they bought, until she bumps into Mme. Forestier, who tells her that the necklace she borrowed was fake, and worth almost nothing.
The story is trying to highlight the value of honesty. If Mme. Loisel had been honest about losing the necklace, she would not have suffered for ten years trying to pay for the new one. However, she was vain and proud, and this prevented her from admitting the truth.