An example of foreshadowing in “The Necklace” occurs when Mathilde and her husband, after losing the necklace, locate the jeweler whose name was on its box. The jeweler reveals that the necklace was not one of his:
The next day they took the jewel case to the jeweler whose name was inside. He consulted his books.
"Madame, I’m not the one who sold this necklace, I only furnished the case."
The jeweler’s dismissal predicts the revelation of the necklace’s worthlessness. This scene is the first hint that the necklace may not be all that it appears, thus anticipating the painful revelation at the end of the story.
What’s more, this scene demonstrates Mathilde’s refusal to look past appearances. If Mathilde had stopped to think critically about her friend’s decision to purchase a box separately for the necklace, she may have come to the conclusion that her friend was trying to hide something about the necklace.
At least, Mathilde could have accepted that the necklace did not correspond to her expectations or assumptions about it, at which point she could have adjusted her course of action. Whether she decided to reach out to her friend and confess the truth or find a cheaper replacement, almost any other course of action would have helped Mathilde avoid the disaster at the story’s end. But she clings by her own volition to the idea of the necklace’s value, despite all evidence to the contrary. This crucial error sets the rest of the plot in motion and lays the groundwork for the irony that dominates the story’s second half.