feinkörniges

Feinkörniges is the neuter singular form of the German adjective feinkörnig and is used to describe a material whose particles are very small. The term is common in disciplines that deal with textures and particle sizes, such as geology, soil science, materials science and ceramics. It denotes a predominance of fine grains over coarser grains and is often relative to the reference material.

In geology and sedimentology, feinkörnige sediments and rocks contain particles smaller than about 0.0625 millimeters (the Wentworth scale). This includes silt- and clay-sized fractions. Feinkörnige textures form in low-energy environments where fine particles can settle, such as lakes, floodplains, deltas and deep marine basins. They often show laminations and relatively low permeability.

Examples of feinkörnige rocks are shale, claystone and mudstone, as well as siltstone; metamorphic equivalents include slate and phyllite. In contrast to coarse-grained rocks like sandstone or conglomerate, feinkörnige rocks tend to be less porous and may be more easily compacted. In practical terms, they can act as sensitive zones for fluid retention and may exhibit distinct mechanical behavior under stress.

In materials science and ceramics, feinkörniges Pulver refers to powders with fine particle sizes. Such materials influence sintering behavior, surface area, reactivity and microstructure. Grain-size distribution is typically measured by sieving, sedimentation or laser diffraction, and thresholds vary by standard and application.

Etymologically, the term derives from fein (fine) and Korn (grain) with the suffix -ig, signaling a texture characterized by small grains.