Final answer:
The literary device used in the excerpt is a simile, which compares the shining wheat crops to gold as transformed by the fairy tale character Rumpelstiltskin.
Step-by-step explanation:
The excerpt "...shone as if waiting for Rumpelstilskin to turn it into gold" uses a literary device known as a simile. Similes compare two different things using 'like' or 'as' to create an image or to express an idea. The sentence draws a comparison between wheat crops that shine in the sun and the fairy tale character Rumpelstiltskin, who could turn straw into gold.
By using 'as if', the writer indicates that the crops' shine is being compared to gold, suggesting their high quality or value without stating it directly.