There are multiple symbols in this poem which contribute to its central meaning. The speaker describes herself as "dust," which she contrasts to the "dirt" into which her detractors would like to crush and bury her name and accomplishments. While dust and dirt may be superficially the same, the distinction is that dust will "rise," just as the speaker intends to do.
There are also various symbols of wealth and industry in the poem, as the speaker describes her vast resources of inner strength, beauty, and power. She describes her walk as being like that of someone who has "oil wells" in her living room. Later, she suggests that there are "gold mines" in her backyard: both of these things symbolize natural resources which can be plundered to make the owner incredibly wealthy.
It is important that both gold and oil are naturally occurring, as this connects to other symbols in the poem which emphasize the natural strength and power of the speaker. She rises like "air" and swells like a "black ocean." The tidal nature of the ocean is like the nature of the speaker's strength. It is notable, too, that the ocean is black, as the speaker is describing the particular plight of Black women, who have been treated so cruelly by history and by society. The speaker notes that, like diamonds, gold, and oil, the strength and power of Black women has been there all along, but now she is able to tap into those resources and "rise" like air.