Parallel alignment of platy grains is what?

Parallel alignment of platy grains refers to the orientation of flat, thin particles, such as clay minerals or mica, in a sedimentary or metamorphic rock. This alignment typically occurs due to directional pressure or shear forces during the formation process, resulting in a fabric that can influence the rock's physical properties, such as permeability and strength. It is often observed in schist and other foliated rocks, where the parallel arrangement enhances the rock's ability to split along specific planes.