The crystal stair—rather, its absence, “Life for me ain’t been no crystal stair” (Line 2)—is the primary symbol of the poem, and all subsequent metaphors are extensions of it. Such a sparkly, fancy staircase would be clean and smooth, in direct opposition to the stair the speaker climbs with “[…] tacks in it, / And splinters, / And boards torn up” (Lines 3-5). The crystal stair also describes something bright and clear as glass. For the speaker, her stair has been opaque and dark, “And sometimes goin’ in the dark / Where there ain’t been no light” (Lines12-13). Ultimately, taking the poem’s historical and political context into consideration, the crystal stair symbolizes all those privileges denied to the poem’s contemporary Black Americans. However, a crystal stair, while an impressive spectacle and symbol of wealth, might also suggest something illusory. While crystal is stronger than glass, it can still be shattered if hit hard enough. The idea that privileged people walk on a crystal stair could indicate a kind of fragility in their position.

Part of what gives power to the central metaphor of the staircase is that the image is inherently linked to human action—and that action is climbing (or, upon mishap, falling).