grain of rock; rift in stone
Refers to the natural grain, texture, or a crack/rift in stone or rock. Often used in contexts like masonry, geology, or traditional crafts.
If you split it along this grain of the rock, you get a clean cross-section.
石目が細かいほど、石材は高級とされる。
The finer the grain of the stone, the higher the quality of the material.
Compound of 石 (stone) and 目 (eye, grain, texture). The exact historical derivation is uncertain, but the combination naturally describes the visible grain or rift pattern in stone.