In geology, a striation is a groove, created by a geological process, on the surface of a rock or a mineral.

In structural geology, striations are linear furrows, or linear marks, generated from fault movement. The striation's direction reveals the movement direction in the fault plane.^[1]

Similar striations, called glacial striations, can occur in areas subjected to glaciation. Striations can also be caused by underwater landslides.

Striations can also be a growth pattern or mineral habit that looks like a set of hairline grooves, seen on crystal faces of certain minerals. Examples of minerals that can show growth striations include pyrite, feldspar, quartz, tourmaline, chalcocite and sphalerite.