The poetic device that is used in "As his classmates teased him about his new glasses, his heart was a stone" is the metaphor.
In poetry, language is used with non-literary meanings that make the poet better express the theme of the poem.
The most common poetic devices include:
This is a common poetic or literary device in which the poet describes a person, animal, object, situation, etc. by comparing this to another element.
Metaphor is used in " his heart was a stone" because the author of this line is comparing the heart of the boy with a stone, most likely to express the way the attitude of the boy changed.
Learn more about metaphor in: https://brainly.com/question/13020675
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