  This paper introduces a new paradigm that integrates the concepts of particle
abrasion and breakage. Both processes can co-occur under loading as soil
particles are subjected to friction as well as collisions between particles.
Therefore, the significance of this integrating paradigm lies in its ability to
address both abrasion and breakage in a single framework. The new paradigm is
mapped out in a framework called the 'particle geometry space.' The x-axis
corresponds to the surface-area-to-volume ratio ($A/V$), while the y-axis
represents volume ($V$). This space facilitates a holistic characterization of
the four-particle geometry features, i.e., shape (${\beta}$) and size ($D$) as
well as surface area ($A$) and volume ($V$). Three distinct paths (abrasion,
breakage, and equally-occurring abrasion and breakage processes), three limit
lines (breakage line, sphere line, and average shape-conserving line), and five
different zones are defined in the particle geometry space. Consequently, this
approach enables us to systematically relate the extent of co-occurring
abrasion and breakage to the particle geometry evolution.
