While the bulk of elementalist's utility comes from theme related functions, part of the extensions protrude into the domain of geoms. Elementalist relies on the extension mechanism of ggplot2 through ggproto class objects, which allows cross-package inheritance of objects, including geoms. These objects can generally be ignored by users for the purpose of making plots, since interacting with these objects is preffered through the various geom_*() functions.

See also