How does J.D. Mcclatchy use imagery in The Vintage Book of Contemporary American Poetry?

Mcclatchy makes mention of Audre Lorde's, Coal, in which she compares words to coal, diamonds, and other inanimate objects. She also sees herself as coming from deep in the earth, like coal, and her words are like diamonds in the sunlight. This is great imagery for discussing the types of words that exist and the way the poet views her own words. "