It is ironic that Mathilde, who prides herself on her beauty and who requires expensive things to feel truly elegant, chooses a cheap imitation diamond necklace to complement her dress—and doesn't even realize how little it is worth.
When Mathilde asks her friend, Madame Forestier, to borrow some jewels, Mathilde is offered her choice of jewelry. After searching through her friend's box of jewels, Mathilde doesn't see anything she likes, even though she is offered jewelry "of exquisite workmanship." Unsatisfied with her options, she asks Madame Forestier if she has anything else. When she is presented with the "diamond" necklace, Mathilde is so exited that her "heart [begins] to beat covetously." Her hands tremble and she can barely lift it. Mathilde embraces her friend for her generosity in loaning her this exquisite necklace and is filled with ecstasy over the sight of the jewels around her neck.
Yet the "diamonds" are cheap replicas and are comparatively worthless. Though the jewels make Mathilde feel beautiful and elegant, they hold almost no value. Thus, the emotions that they elicit are ironic; Mathilde feels that the necklace makes her worthy of attending the ball, yet she is elegant and graceful despite the fact that she wears worthless jewels.
Mathilde believes that she was destined to enjoy the luxuries of life, yet she fails to demonstrate an ability to recognize authentic jewels from cheap replicas. This is an ironic twist that costs her the very beauty that she takes so much pride in early in the story.
The irony in this short story is that while Mathilde and her husband spend a decade working to replay the loan they took to replace Madame Forestier's necklace, which Mathilde lost, the original necklace had been close to worthless. In addition, Mathilde's attempt to improve her social standing by being seen wearing the necklace backfires and causes a decade of sacrifice.
It is Mathilde's dissatisfaction with her life of mediocrity that leads her to a life of poverty, in which she must do heavy housework and hard labor. Instead of elevating her to a status of wealth and envy, borrowing the necklace lands her in a far worse predicament than that which she was in at the beginning of the story.
I would argue that there is also irony in the fact that Mathilde so craved the affection and attention of society, when all the while, she had a loving husband who would do anything for her.
She eventually learns that the necklace she borrowed was worth, at most, 500 francs. The replacement, which had cost the whole of Monsieur Loisel's inheritance as well as sizable loans, was 36,000 francs. If Mathilde had agreed to go with her husband's suggestion of using flowers rather than jewelry to complement her outfit, the couple could have spared themselves ten years of debt and heartache.
There are several examples of irony that can found in "The Necklace." One of the first examples of situational irony takes place when Monsieur Loisel informs his entitled wife that they have been invited to an exclusive ball at the palace of the Ministry. He expects his wife to be pleased by the good news but is crestfallen when she responds with scorn. Mathilde Loisel bursts into tears and laments that she does not have anything pretty to wear, which is why she doesn't want to attend. Mathilde's reaction to the invitation is ironic because her response is the opposite of what her husband expected.
Another example of situational irony concerns the fact that Madame Forestier's necklace is simply a cheap imitation and the Loisels take on considerable debt to replace it with an authentic necklace. It is ironic that the Loisels work for ten years to pay off a genuine diamond necklace to replace something that was worthless.
Essentially, the Loisels ruin their credit and stress themselves out over nothing. It is also ironic that Mathilde descends into further poverty after borrowing the necklace. Mathilde was already dissatisfied with her humble life and hoped that attending the ball at the Ministry would bolster her reputation and status. Ironically, Mathilde and her husband experience significant financial distress after attending the ball. It is also ironic that Mathilde loses her beauty after ten years of labor, which was her only valuable asset.
Madame Loisel thought that by wearing what she thought was an expensive necklace to the Education Ministry ball, she'd be going up in the world socially. Unsatisfied with her social position and believing herself entitled to better things, Mathilde genuinely thought that the necklace would provide an entrée into a rarefied social world that it would allow her to impress the upper echelons of society with her grace, beauty, and elegance.
In a case of supreme irony, however, things don't turn out like that. Instead of going up in the world socially, Mathilde falls right down the social ladder. All this was because the necklace that Mathilde wore to the ball—and which she subsequently lost—was actually a fake.
But because Mathilde was blissfully unaware of this uncomfortable fact, she and her husband go into considerable debt in order to buy a replacement. In other words, they pay for an expensive item that was a replacement for a worthless piece of costume jewelry. As a result, the Loisels are plunged into desperate poverty, the exact opposite of the condition in which Mathilde expected to find herself.
Here we have a prime example of what's called situational irony, where the outcome of the story is the opposite of what we'd normally expect to happen.
In the short story "The Necklace," Madame Loisel has lost the diamond necklace that she borrowed from Madame Forestier. In a panic, she and her husband scrape together enough money to buy a replacement. She had to work hard for many years to repay the loans, having to give up her wealthy lifestyle and scrimp and save for ten long years. When she happens to meet Madame Forestier in the park after those hard years, Madame Loisel can't hold her tongue. She blames Forestier for her hardship, and explains what she had to do to replace the necklace.
The irony: the necklace was costume jewelry, worth very little money! The irony in this story can be called situational irony.
Irony is a very effective device in literature and exists in two forms. Verbal irony is a method in which "statements often convey a meaning exactly opposite from their literal meanings." In situational irony, which is what gives "The Necklace" by Guy de Maupassant its stunning twist in the final lines, "actions often have an effect exactly opposite from what is intended."
Madame Mathilde Loisel is a woman who feels misplaced in her life. She settled for a marriage with her husband Monsieur Loisel solely because she was not able to marry "higher." She resents the simple home they share and its sparse, plain furnishings, and while her husband dines heartily, she dreams of the riches and finery of the life she feels she should have had. So resentful is she of her present situation that she even spurns a friendship because the woman is wealthier than she, and the envy this creates for her causes her intense suffering.
When her husband presents her with an invitation to a ball, and then with the money to buy a new dress that she feels will be worthy of the image she wishes to present, she still feels she cannot go without the proper jewelry. Her husband, wanting nothing more than to make her happy, suggests she borrow a piece from her friend Madame Jeanne Forestier. Rifling through the jewelry, she fastens on a beautiful diamond necklace. With this stunning piece adorning her, Mathilde feels she can truly look the part she wishes to portray.
At the ball, Mathilde lives out her fantasy. She is admired, envied, complimented, and sought after. However, when arriving home, she realizes with horror that the necklace is missing. Following fruitless searches, she and her husband buy a replacement, and Madame Forestier is not told of the loss. This begins a ten-year endeavor to pay back the debts accrued. Mathilde, during this time, knows poverty, sacrifice, and back-breaking work, and the woman she becomes is a mere shadow of the woman she was before the ball.
When she encounters Madame Forestier after the debts are finally paid, her friend is shocked to see these alterations, and when Mathilde relates the story of the missing necklace, the replacement, and the years of toil and deprivation, Madame Forestier reveals the stunning truth - that the lost necklace was simply costume jewelry, worth a mere fraction of the replacement piece.
This is the situational irony of "The Necklace." The piece of jewelry that Madame Loisel used to escape the life she had for the duration of the ball was the vehicle for her descent into the life she now lives - "an effect exactly opposite from what (was) intended."