What is the mood and theme of the story "The Necklace?"

The theme of the story The Necklace is dissatisfaction and
ambition gone awry due to the need to appear to be someone (or something) that you are
not.

Mdme Loisel is a woman who could live comfortably if
only she were less ambitious and irrational in what she claims to be
"happiness".

When an invitation to a party arrives, rather
than being considerate and rational, Mdme Loisel complaint about not having enough nice
clothes and jewels with which to impress those attending. After borrowing a very glitsy
necklace from a friend, she finally looks as regal and rich as she wants, and shines at
the party. When she realizes she loses the necklace, she works hard to the point of
poverty to replace it. In the end, the necklace, just like the ambition of Mdme Loisel
ended up being a fake.

The mood in the narrative is of
depression and negativity with the whining and complaining of Mdme Loisel and the
desperation in which she fell afterwards when she ended up in deep poverty trying to pay
for what she thought was a real diamond necklace. In the end, when we find out that the
necklace was a fake, the mood is cruel, sad, and almost despairing. It is not a happy
reading, but is a very good one.