Which shape classification indicates particles that are primarily angular?

The classification that indicates particles that are primarily angular is indeed angular. This term refers to particles that have sharp edges and corners, which results from limited transport and weathering processes that would typically smooth out such shapes.

Angular particles are typically found in environments where they have not been subjected to extensive erosion, like in freshly broken rock or in environments with minimal movement by wind or water. This lack of smoothing signifies that they have retained their original, jagged forms.

Subangular could be mistakenly perceived as similar, but it actually refers to particles that are somewhat rounded off – not entirely sharp, but still not fully rounded. Rounded particles, as the term suggests, are those that have been significantly worn down, losing their sharp edges and corners. Platy refers to flat, sheet-like shapes and does not specifically indicate angularity.

The distinction lies in the degree of angularity and how particles are shaped by natural forces, making the definition of angular the most accurate for identifying those particles that primarily exhibit the sharp-edged characteristic.